Thanks a lot!
Regarding the first point, it is a fixed 8 second period, but the timer idea is nice, didn't really think about it back then!
About the guns, I managed to add 2 others (sometimes when you land on a white or blue side it spawns an item in one pip, it could either be a shotgun (more projectiles), machine gun (faster fire rate) or the base gun, everytime you pick a gun again it increases one of its attributes), but it got a bit rushed so I suppose most people haven't noticed it.