Are screws holding down the acrylic necessary? (Qanba Q1)

Hey guys! My humblest apologies if this was answered elsewhere, I promise I did give the search engine a try!

I just got a Qanba Q1--I wanted a fairly inexpensive stick that would be easy to modify with some custom art. I took it all apart and applied a "lami label" from FedEx/Kinko's, and it worked out great! But as I was cutting holes in my art, it occurred to me that the screws that hold down the acrylic sheet maybe aren't necessary, since the buttons also hold it down to the case quite firmly. So I left them out! Less holes in the art seemed like a good thing to me, but I wanted to make sure I wasn't doing something I'd regret, either.

Thanks!