Need Advice: Re-Ripping ALL of my CDs using ALAC/Apple Lossless

Question

I need advice from some experienced users (having searched for answers for a couple of days and not finding a comprehensive solution).  I want to "upgrade" my iTunes library (95% of which is from my CD collection) from ACC (the default iTunes file format) to ALAC (lossless format). I realize that music purchased from the iTunes store will remain in ACC format, but I am using this opportunity to "archive" or "digitize" my CD collection.  I have some, but not a lot, of non-critical tags, album art, etc. set up with my current library.  I will be saving all of the music files in a new folder on a single hard disc on my network (with backup).  I use iTunes Match.  I have Windows PCs, Macbook Pro (OSX), iPhone, iPad, iPod.  Given these factors, I am seeking recommendations:
Does it make sense to "start over" and create a brand new iTunes library?
(this would certainly give me time to complete my project while still using my current iTunes library)
If yes, what do I need to do in order to "activate" the new library once it is complete in order to reset iTunes Match and all of the other devices using my iTunes library?  What complications can I anticipate?
If no, what is the best way to replace the existing albums in my iTunes library with the new ALAC files?  Do I simply insert the CD and import it with my new settings?  Will iTunes take care of the rest (saving the new file, deleting the old format, matching tags, etc.)?  What complications can I anticipate?
What are the advantages/disadvantages of allowing iTunes to "Keep iTunes Media folder organized" and "Copy files to iTunes Media folder when adding to library?"
Any other suggestions, warning, smart alec remarks?
I know there are a lot of questions bound up in this post, but if you have converted your iTunes music collection to one of the lossless or uncompressed formats, I would love to learn from your experience (and am guessing others will as well).  Thanks!

Answer 1

In most cases you should be able to re-import your CDs to the existing library - iTunes will automatically replace your media files and retain all previously added metadata.  This does depend on the library being the same one as you originally imported the CDs in AAC format (i.e., the same computer or the result of a complete library migration).  You should experiment with a couple of CDs to verify this behavior - I've done this successfully to "update" some of the older content of my library which had been imported as 128kbps AAC to 256kbps..
Obviously this approach will put your media into the existing library media folders, which is going to be the simplest approach.  If you subsequently want to move the library to a different drive, see turingtest2's user tip on Make a split library portable.  If you're concerned about running out of disc space on the drive that currently hosts your library, you could follow these guidelines to move the library to a second, larger drive before starting to re-import using ALAC.
This is the approach I'd recommend, though there are a couple of other possibilities:
Create a new, empty library on the second drive by holding down SHIFT as you start iTunes; when you see this prompt:
click on Create Library..., navigate to the second drive and create the library there (best approach is to create this in a new iTunes folder in the root of the drive.  This will guarantee "clean" imports but you'll not be able to re-use any metadata, artwork, playlists, etc. contained in your current library.  To switch between libraries, SHIFT-start and use the Choose Library... option to select the library you want to be active.
On the second drive, create a folder called iTunes in the root and a folder called iTunes Media inside this.  Then, with iTunes running against your current library, select Edit > Preferences > Advanced, change the iTunes Media folder location to the one you've just created (i.e., X:\iTunes\iTunes Media, if the second drive is "X:".  Also make sure that the Keep iTunes Media folder organized and Copy files to iTunes Media folder... options are checked.  When you re-import your CDs the media files should be placed on the second drive ... note, though, that I've not verified that this approach will work - in theory it should do but you should definitely test with one or two CDs before going any further.  This approach will result in a "split" library where your library database is on the C: drive and the media divided between drives (since your iTunes Store purchases will still be on C:).  This is generally not a good idea (if for no other reason than making creation and maintenance of a backup of your library more difficult).  Again, tt2's notes on Make a split library portable describe how to bring the library into a consistent, well-formed layout.