You can change the size of stuff by hitting R3 (right stick button) on the UI menu I believe, or it might be while you have it selected (by hitting select a few times), I forget which. I have a lot of things moved and resized so they aren't in the way (like the Alliance boxes for CT), and I think every HUD item can be lowered to 60% (or was it 80? I forget) and raised to 120%.