You can eat things like french fries and pizza but it's all about moderation!
Right NOW you might not beable to because of your potassium levels, BUT once they have stabilized I am sure you will probably be able to re-introduce them... They just can't be your staples anymore... But, be sure to ask your doctor whether once your levels have stabilized you can eat them again or if they will send you way out of whack...
As far as remission... From what I can tell, just as Lupus is different for everyone, so is remission... And every doctor's definition of remission... Sorry I'm not much more help!!
Welcome to the board!!