Known. Hard to fix because there is a silent period between boss fights, and the game doesn’t know in advance which music is going to be played next. It’s on the list, though.
That defeats the purpose of the wave, which is to change sides.
It’s not really music, so I don’t know…
Makes no sense.
You make is sound like less overdrive is better. It’s not. You probably mean less heating. I don’t want to mess with that, overdrive should not have a long-term benefit over regular firing. This is a very fundamental principle.
Nice, but hard.
THere’s equipment that increases your collection radius.
Fixed in v.52 
Bug
I haven’t awarded medals yet.
It takes a while for the overdrive gauge to empty. But the overdrive is not actually active.
Sorry, that’s a limitation of the enemy spawning engine for this particular wave.
That’s up to the community to decide. The alternative is to rescale easy/medium/hard to be e.g. 0-40% 50-90% and 100-140%