So almost every other time that i log back into the client my cast bars are reset not sure why this is happening and also while playing a message will pop up sometimes saying that my computer's memory usage has exceed its healthy limit but i have almost 400gigs still open? so confused O_O
What I'd suggest is that when you first log in, get your action bars set the way you want them. (I'm presuming that you're talking about skills or other things you've added to the bar slots.) Change classes, do the same things there. this also includes expansion of the bars--to add slots--and activating more or all of the bars. Then log out to save the changes. If you should happen to have a client crash before you save the changes and settings, they will be lost and you have to re-do them.
As for the "memory message", I think this is a "feature" that RW added to the game with the Chapter V expansion. It may be intended to hint that you're heading for a crash, or that you have too many background applications and/or processes running, and your computer is short of free system RAM (not HDD storage space, which is entirely different.) I don't happen to know if it's percentage-based, and it may well be. But it's not a warning that Bad Things are going to happen with your computer.