Can I create a OSX boot clone on an external thunderbolt drive and retain the original internal install as a bootable option for the rare times the MBP is mobile?

Question

Continuing my reaserch into the best upgrade options.
I'm looking at thunderbolt storage.   But just just discovered that thunderbolt is apparently bootable...
As the 2.5" sata HD in the MBP isnt the speediest thing in the world, I was wondering if people thought it was a good idea to clone my OSX install to a thunderbolt drive (currently contemplating a 4tb mirrored (2tb resultant vol) with a 250gb osx partition 250gb bootcamp partition and dividing the remaing space for time machine and win backup)
the MBP mainly lives on the desk in the office and rarely is dis connected from its cluster of attachments.   But for when i do take it walk-about  can i leave the origional OSX install on the internal HD for mobile use?
sorry for all the questions ( I feel like a noob again)
also is there anyway to have two or more bootcamp drives? i'm not talking partitions within bootcamp but another complete bootcamp in its entirity....
ta
Stephen

Answer 1

so once I've migrated bootcamp to the external thunderbolt drive I can use the space it occupyed on the internal HD for a partition for my home directory and all those other sharable assets...  point the internal and external copies of OSX at this and i't will remain current regardless of weather i'm connected to the external drives?
That's the general idea but something's you need to be concerned about.
1. I am not familiar with bootcamp so I do not know whether it can be run from an external drive.
2. Before doing anything about moving your home directory make sure you backed up your original stuff on yet another disk.  Since you never attempted this before you could easily make a mistake and be hung out to dry if you cannot start over by reverting to the backup.  This is an important step not to be ignored.
3. Contrary to what you read in the various web sites about moving your home directory, and there is plenty of them (google "move os x home directory"), I don't agree with the way they say to do the move, i.e, drag the home directory in the finder to the new location. 
When I move the home directory I am always concerned about ownership and permissions info on the files which can be changed by simply moving the home dir in the finder.  So the safest way to protect against the is to use the terminal (in utilities) to create what's called a tar.gz (gz stand for gzip just another form of compression like zip is a form of compression) of your home dir and move tht tar.gz file to the new home dir location and then expand it.
In terminal I would do the following (assume YOURACCOUNT is your current home directory):
cd /Users
tar czf  YOURACCOUNT.tar.gz YOURACCOUNT
This will create the file YOURACCOUNT.tar.gz which you can now safely move to your new location.  Not only that you now have a backup copy of your current home dir in that compressed YOURACCOUNT.tar.gz file.
Say you move YOURACCOUNT.tar.gz to a new drive called, NEWDRIVE.  Then in terminal,
cd /Volumes/NEWDRIVE
tar xzf YOURACCOUNT.tar.gz
Now your YOURACCOUNT home directory is safely moved and all it's permissions and ownerships are persevered.  You still of course need to fix up the Accounts information to point to this new place as mentioned in those many articles on the topic.