this is way too overkill
There's a lot of things that it's FAR from a complete strategy against, with either version. It's just one piece in a larger machine. But it's a fun one! xD The rock boss with the -3 damage taken modifier is immune to the damaging version. Large crowds only take one hit at a time, and while it's high dps, there are ways to get multi-target attacks higher during group fights.
I just find things like this one really amusing. Finding ways to take the min-maxing to the extreme is a big part of the fun of a game like this one, at least for me. From your screenshots, it seems like you're enjoying it too!
Stacking the -1s mods never drops the cooldown below 1s - I tried that already. If you could, that would instantly break the game regardless of having the +2 damage, because you'd hit for infinite damage even with the baseline of 1. The instant the fight starts, you'd hit for 1 damage, then with no delay, hit again, and again, and again, and again... no matter what HP enemies have, they would die at 0s if you could reduce the cooldown that far.