pretty soon the game will enter into early access and just looking through various forums it looks like it will sell quite a few copies. for people who genuinely want to give feedback, will this be done through game e-mail, here on forum boards, discord or some other way?

...and while we are at reporting problems, looks like on steam store page the purchase button is missing :P

The game will send its data to their servers directly. And there will probably be an early access special area in the forums. That's what we had for DOS 1&2.

Raze said awhile back they'd be opening up other forums for things like feedback posts/threads and reporting technical issues and the like (you can look down the master forum list and see what's there for their legacy games to see what's likely to be in play).