It sounds like you got pretty unlucky with your first sets of mutations with the rejected arm and sack feet. Sack feet is the only mutation that REMOVES dodge roll so don't worry about that happening often. Some of the other dodge rolls are immensely useful compared to how that one is so un-useful, but we'll keep balancing the RNG of it as we keep getting feedback. No matter what dodge roll you have though the level exits should be reachable but some secrets/stockpiles do become un-reachable with certain dodges.
We'll definitely tweak the transmitter arm soon as well, it should definitely be able to pop geysers and perform basic melee functions just with reduced damage. It seems like the range is too low now or something though.
The Hailshard meteors are a randomized weather trap that we want to be punishing if you don't respect them and also occasionally able to be manipulated by your positioning when they drop but they're maybe a bit too punishing now.
You're right about the laser too, it's just not hooked up yet. Someday it will be but there's not much of an advantage to turning it off for now so we haven't prioritized getting it working.