I don’t think Clean Sweep is possible on that wave, because IIRC Feathers also count as enemies, and you can’t kill those.
Because it moves you away from the screen edges, where enemies appear. Safe areas are only meant to help with initial positioning of your spacecraft for the start of the wave, and aren’t really valid after 1-2 seconds.
Changed in v.111 
Idea
Changed in v.111 Idea
It’s possible, but I prefer the way it is now.
It appears even slower now and from the top of the screen, so no.
Unnecessary.
Changed in v.111 Idea
Changed in v.111 Idea
No, that might lead you to move on top of the zone, which will get you trapped.
Slobs don’t directly aim at you, so I think they’re fine for now.
Changed in v.111 Idea
Those explosions are not instant – they have shockwaves.
It’s correct. The Destruction meter uses the “dark” color (which is normally used for list items).
If you’re in keyboard mode (press one of the arrow keys first), you can use A and D
Added to v.111 Idea
It’s fine. You can’t get Pecking Order for everything, but you can get it for 1-2 columns if you try.
That’s going to change the strategy for the wave, but I like it. Changed in v.111 Idea
Barriers move so slowly so neither type of zone is needed.
Again, barriers move slowly and you can clearly see them from the sides first (before they come up from below)
Unnecessary
No
They could, but no.
Those disappear when you kill the outer enemies
Move out of the way?
Changed in v.111 Idea