Opinions:
I do not like the idea of Angel of Speed, Rushing, whatever you call it where the game is NOT turn-based but instead more real-time. Unless the time periods for a turn were made longer (5 or 10 seconds until a turn is forced), and a Pause key was added, I would not want to play that Challenge. I understand that it is intended to be a challenge, but it breaks one of the core elements of the game (turn-based game), and I do not feel that the challenge would be that much fun or different. I understand, AoB and AoPc break core elements too, but they are different, and fun... in a masochistic way. They allow for unique gameplay tactics, and fun stories for your mortems. Angel of Speed would be "No time to use inventory, no time to be strategic, no time to look at past message log, no time to think." I just don't feel that it would be fun, for some people at least. And some Challenges (AoD at least) were removed, I believe because no one really played them, or they were not different enough. Maybe I am wrong though, that's why this is my opinion.
Angel of Stress is a little bit confusing, and I don't think that powerups should punish the player.
Angel of Traits sounds good, as long as powerful enemies do not get overpowered. Arch-Viles with Hellrunner, Mancubi with Eagle Eye, a Baron of Hell with Tough as Nails plus Red Armor plus Large Health Packs, those could happen, but they would make the game almost unplayable, unless the traits you can get really make you just as powerful.
Angel of Arena would get boring after awhile, starting at the same place, having the same kind of enemies in the same basic places.
AoMcD..? Haha. I assume the screen would scroll then? Eh, that would kind of break the game.
Angel of Gravity is confusing, and doesn't sound like maps would be fun.
For Angel of Indestructible, I think barrels should be destructible, but not destroying things nearby except enemies. Does "Floor tiles" mean that acid and lava won't appear from barrels, or what?
Angel of Rambo sounds good, unique weapons would be broken in most instances, but that could be ok. Using regular weapons on enemies, and saving Uniques for the tougher guys, I guess. Melee characters would work well then, but Shottyman would be a little bit useless, along with Combat Shotguns.
As for my ideas, I have posted all my Challenge ideas awhile ago, haven't really thought of any others since then. So I thought I would give some input on the ideas shown here, since if we just list off ideas and no discussion results, the ideas will probably not be considered. At least as far as I can see.
Oh and sorry for the length. :)