i was wondering if 1/8" lexan is too thick for crankbait bills, im making 2/ 2.5 " balsa baits? the lexan was free so im hoping it will work, maybe if i rounded the edges? or will i even need to?

I use 1/16" Lexan on all bass baits but some guys use the thicker stuff.  To me, it's as much a balance issue as it is about lip performance.  Little differences in a crankbait can make big differences in its performance so I think all anyone can say is - Try it and see how it works for you.  I wouldn't round the edges but some guys bevel the under side of the lip to make the leading edge sharper, which is reputed to give the lip slightly quicker action.  Of course, that also makes the lip wear quicker, so like a lot of things, it's a trade-off.

ive done 2 baits with the lexan bills and they seem to swim ok in the bath tub but due to weather i havent got a chance to actually give them a run yet

Personally I would not use the 1/8 lexan, I like to go as thin as possible to help with depth/balance.   I'm sure it will work just fine but will add tiny bit of weight to the nose of your baits.   For me I just like the look of 1/16 lexan and 1/32 circuit board bills.