Level 22 - need hints

It would have been nice if game explained what that number in box means: https://postimg.cc/zVmmsRQx/ed832c38 I did found out eventually, though You can remove 2 (in this case) numbers from grid

Can't figure this one out. I know I have to get rid of exactly one even number but nothing seems to work.

If you combine 2 squares with same numbers they become white (unless they are the final squares). Why?

Am i the only one who thinks 6 .exe's in task manager is kinda fishy?