How does one merge existing IPhoto 11 Libraries on an External HD?

Question

I have an IPhoto 11 Library on my IMAC.  I have multiple IPhoto Libraries on my external HD.  I use Snow Leopard 10.6.8, IPhoto 11 (v. 9.2.3).
I am not sure how I got them, other than Apple at one point backed up all my files onto my external Seagate HD in order to completely wipe out and do the most extensive reinstall they could due to a malfunction of Time Machine located on a Lacie External HD.
In addition, I must have backed up my IPhoto Library onto my Seagate HD.
My question was how to merge two or more libraries located on my Seagate HD, backup my IPhoto Library onto the Seagate, and eliminating duplicates.
I think I have found my answer after 3 days of searching YouTube, Apple Discussions, Books, google.
It may be long and convoluted but I think I am doing nothing wrong.  I wish comments as to improvement or flaws in my procedure.
From what I can glean, IPhoto does not permit merging of multiple libraries, that external programs such as IPhoto Library Manager and IPhoto Duplicate Annihilator are what most recommended.  In addition, Aperture vs. Lightroom were discussed.
My solution using just the external HD's and IMAC for transferring photos in their original format (RAW, Jpeg, etc) from my IMAC to an individual IPhoto Library on my Seagate HD.
1.  Locate proper IPhoto library, the one on my IMAC by holding the ALT/Option key then depressing and holding the IPhoto Application key located on the Dock until a window pops open, slide my mouse to the window to the line that says, "Open" and releasing only the mouse key while still depressing the ALT/Option key. This will open a window which will permit me to select from the different IPhoto Libraries.  If some bear the same name, a look at the pathway on the bottom of the window will show which are on the Seagate HD.
2.  Click on the library desired to be opened, in this case, the IMAC IPhoto Library.  This will open IPhoto.
3.  Select an image, from the Events, Open that image, Open the Info pain (lower right) noting name of file and file size, example CRW_0555  6.5mb a Cannon Raw file.  Click on "Edit" which will permit editing.
Hover over image of photo and Right Click with Mouse, window will open, slide cursor down to "Duplicate" the photo and Left click.  A duplicate RAW file will be made. 
4.  Click on Info to close out the Edit mode, Click on the Date Arrow (Upper left of IPhoto window) to get back to the name of the event.
5.  Highlight the selected photo or photos, File > Export, select "Original", not the Jpeg that automatically appears.
6.  Click Export.  New window will appear, in my case telling me it will go to Pictures.  Move cursor to window and select via arrow, Desktop to export to.  The duplicate RAW file will now appear on your Desktop.
7.  Close IMac IPhoto Library.
8.  Follow steps 1 & 2 above to Open the desired Library on the Seagate External HD.
9.  Drag the RAW desktop Image into IPhoto Library, either into Events or Last Import.
10. Close IPhoto Library.
11. Reopen IPhoto Library by clicking on the IPhoto App located on the Dock.  The last library opened, will now be the default, which was the Seagate External IPhoto Library, will open.  Click on the RAW image you imported from the Desktop, verify through Info that the Image name and file size and type are exactly the same, in my case, CRW_0555  6.5mb. 
12. Drag Image on the DeskTop into the Trash. (Empty at will).
13.  You have now taken a duplicated Image or group of selected duplicated images which you created, which you have highlighted in IPhoto on your IMac, dragged them to your Desktop, switched libraries to a selected library on your External HD. and transferred an exact copy into that external IPhoto Library.
Utilizing this basic technique, you can now do any of the following.
Backup your entire IMac Library onto an External HD into a library of the same name.
Take one or more selected images, highlighting each image in an particular Event on your IMAC HD.
Transferring an exact copy of those Images into any particular IPhoto Library on your External HD.
Transfer one image in an external  HD IPhoto Library-1 into another external HD IPhoto Library-2 on the same HD (by simply opening up  HD IPhoto Library-1, selecting photo, duplicating photo, Exporting Photo to Desktop, Closing IPhoto, Switching Libraries to IPhoto Library-2, opening that Library, dragging Desktop photo into IPhoto Library-2.
You can identify all IPhoto Libraries on all drives and rename them as follows.
1. Open Finder and locate IPhoto Library on the MAC HD under "Pictures", looking for the IPhoto Library Icon in the My Picture Folder (at least in my case).  It is simple to find, as it is brightly orange colored and as a description it states, "IPhoto Library"  not to be confused with the similar Icon which has a camera in front of it, identifying it as an Application.
2. Double click on the IPhoto Library name and rename it.  I named mine "IPhoto Library IMAC-1"
3. In Finder click onto Macintosh HD.  In the Search field, type in "IPhoto Library".  All of your IPhoto Libraries will show up that are on your IMac and on any currently connected HD's.
4. I renamed them, example, IPhoto Library Seagate 3TB 1, IPhoto Library Seagate 3TB 2, IPhoto Library Seagate 3TB 3, IPhoto Library Lacie, IPhoto IMAC-1.
Items like Library6.IPhoto of only 4Kb (when one opens "Get Info" in the finder, is listed as an "IPhoto Library" "Kind" of file type.
When opened, it appears to contain full size images in a full size library, so perhaps this represents the icon pointing to the "Last import".
Can anyone tell me what that represents?  I will not rename nor delete that.
By keeping the names of the IPhoto Libraries, consistent, descriptive of type of drive and the name of the Library you have assigned to it, then simply opening Finder and searching for "IPhoto Library" and looking for the colored icons, one can see, at a glance where each is located (by looking at the bottom of the Finder window for the path which will tell what drive it is located and the pathway to reach it).  One will see each of their names.
This saves me from purchasing 3rd party programs to locate duplicates, to merge and establish and rename libraries.  This probably will work well if I do no more than a batch of 50 pictures at a time. 
It would appear that I will only do this massive procedure one time, making one library on my External HD, eliminating all of the duplicates as long as I let them have the same first part of the name, i.e., CRW_0580, and simply making a search.  They should all pop up in my search.  I can add on additional suffix names such as CRW_0580edit1, or pano, etc.
Does anyone see anything flawed in my above procedure?
Is there an economical easier way?
I am not sure I want to purchase Aperture, which apparently is overdue for an upgrade.  I may want to wait.  I may decide on Lightroom, my Adobe Photoshop Elements 10 provides for far better editing capability than IPhoto, at least in terms of exposure corrections.
Pros as I see it to my method - 
Inexpensive $$$, no extra cost for extra programs
Full manual control as to what gets transferred, picture by picture
Cons
Seems quite timeconsuming for a first runthrough of the 3,000 photos, both individual and edited.
May have unforeseen consequences that I am not aware of.
Advice is appreciated.  Though I have had this machine for several years, I am still trying to learn and have limited understanding.  I find written instructions hard to understand and follow, escpecially not understanding the differences between different what I believe to be synonymous terms.  I find YouTube videos informative but now answering all of my questions.

Answer 1

The duplication is unnecessary. Exporting creates a duplicate of the file. So now you'll have a duplicate of a duplicate. Exporting is not "working on" a file.
No it's not merging, it's exporting from one to the Finder and into another. No matter what lose something. If you export the Original you leave behind all the work you've done in iPhoto. If you export anything else, you lose the non-destructive editing and the ability to revert to the original. With merging you preserve that work. Yes, you can trash the old Library when you have completed the manoevre but no it's not the same thing as merging.
This User Tip
https://discussions.apple.com/docs/DOC-4921
has details of the options in the Export dialogue. But in brief:
Current gets you the iPhoto Preview, used for sharing via media browsers. It's a jpg, medium quality missing metadata. Original gets the file you imported, unchanged and then you can export different version of the current version at different qualities. If you choose to export anything except the Original you do not get a Raw. There's no such thing as an "edited Raw", and you lose the connection between the original and the exported version. That means you've taken a non-destructive workflow and turned it into a destructive one.
The Tiff will certainly be higher qulaity and less likely to suffer generational loss in future editing but the file sizes are vast, often more than 10 times the size of the jpeg.
Put it this way, it would be cheaper to buy Library Manager than the disk you'll need to contain all the Tiffs. Unless you plan on a lot of editing, I'd go for a high quality jpeg as a reasonable compromise.
To be clear:
So, I guess my new question is, how can I edit the Raw image and keep it in a RAW format that IPhoto recognizes so that I can reprocess without any loss at a future time, or is it that once you edit a RAW image, then it is no longer a RAW image?
Once you edit a Raw it can no longer be a Raw. End of.