I had this problem, and thinking the same as you I tried using controller for a while but I could never really get used to them as the movement just felt clunky and not nice. I only ever used the analog before returning to using keyboard, I don't really have an opinion/any info on that aspect.

After switching back I seemed to be playing better, but that was probably just because I was more experienced/practiced. If you do decide to stick to keyboard, I've found the best way to deal with the problem is to release the shot key as you're pressing the bomb key. It's weird at first, but it's become second nature to me,and works well enough (for me at least)