Honestly...can we barely stand up if we're naked and have the flaw Weak? Or can we carry some basic supplies but not carry heavy weapons or a lot of supplies and such? How 'weak' is Weak?

You can be as weak as you want to be. The whole point of the flaw suggestions is to make your character more realistic. You are not forced to take the flaws, but it is definitely lovely to find characters with a few corks and drawbacks. It makes your character real. But in the end your character is yours and you can changed to weakness flaw to the level you need.

Okay. I think I know how I'm gonna play him then. Thanks, Anika. :)

not a problem :D have fun!