Help w Star Wars the Old Republic...

I'm on a Dell Inspiron 1520 on windows 7 64bit...
Intel Core 2 Duo 2.00mhz
4 GB RAM
NVIDIA Geforce 8600 GT
Sigmatel Audio

Just started playing star wars the old republic- my first pc game...
Have 2 things I need help with for now:

1) There is this terrible crackling sound; any ideas what the problem could be?

Is it possible the visual setting are too high and crackle/staticie sound is from hardware performance issue?
I don't think this sound would come from a performance issue?

2) When walking around the world, there is significant stuttering and temp glitching (character acts like walked into invisible wall)
A) Is this a hardware performance issue? I have visuals turned down to LOW, is it possible that's too taxing?

B) Server lag???
Does your character just stop moving when the server is too slow or lagging? Does this happen frequently with this game?
Is there anything that can be done on my end to correct?

Thanks everybody...