If the first two things are implemented already, then I think that just needs to be communicated better. I had kind of suspected that might be the case with the projectiles and did invest a bit but gave up when I kept encountering red shots.
As far as performance goes, I am using Chrome. 32BG ram, Ryzen 7 3700x for the cpu, and a 3070ti gpu. It's the whole game, I noticed it instantly when I started walking when I first played and before enemies really got a chance to spawn.
I don't mind the upgrade "procs" being a bit hidden, it makes it fun and surprising to discover them, it gets easier to get them with the bottom shop upgrades. I do agree that the damage to projectiles behavior, wording and color code is a bit confusing tho.
I'm sorry you had performance issues, I have no idea how to replicate or fix it, in my experience even on a very low end PC it should run fine :/