According to this, you can go and grab another one every 12 hours of character time. If the finger is making you crash, I would suggest you stop using it until they fix it.
I don't think you can. It's possible to explore each of their quest lines to a certain degree and not have anyone go hostile, but if you want to finish the main story you have to pick one.
She didn't really specify which version of Tactics Ogre she was referring to, though. The PSP port isn't so bad, but the one on PS1 was pretty damn harsh.
1.) Dodging is all about timing. Think Guild Wars 2, except you have to be a little more precise.
2.) Blocking is a Warrior thing. I don't know about Berserkers, but Guardians are able to block. If you use a 2H weapon, the block meter depletes faster.