Hi, I am in the final week of a CELTA in Prague. I have been told that I have passed- I've met all the requirements- but don't yet know the grade.
It does take up all your time if you want a good grade. If you just want a pass then I'm sure you could spare 8 hours a week to socialise or something.
If you intend to work in the EU then it will be a definate advantage to be an EU citizen as work permits can be time consuming for school administrators but most good schools would rather have a good teacher than a bad one who is from the EU!
Outside of the EU it shouldn't be a factor!
The CELTA can be fun but its hard work and in the final week there's plenty of time to party unless you have to resubmit assignments from the previous week!!!

Good Luck!
Some tips: PAIR CHECK! USE CCQs and USE ICQs! (these terms will make sense when you do the course!)