First off I'd like to say... "Zombie Power!" <EG> Y'all done it now...
I'd also like to say I and mostly 'we' are fine with whatever TFP wants and implements.
A3: Seems a bit unnecessary.
A7: "just because."
B3; Specifically: "poison gas, explosive gas, lava." For me it would seem to be 'expensive' in many aspects especially early in game. Not to mention all the 'added' things to the game that would have to be worked out...
B4 I'm not a fan of "Insanity" especially since my stance is: If you're in the ZA - you're either going to adapt or die and that 'should be' before the game starts! It would also mean a 'constant' check and on the players side a constant battle against insanity. "You're born and raised in the ZA! Humans greatest quality is to adapt and therefore this insanity is not necessary.
B5 - "Farming" is an integral part of the ZA... Nuff said, besides its fun and does help involve other types of players.
For C2 - I'd say that underground caves and POI's don't need to be too complex. Just having some would be a big bonus! I'm a great fan of C3!!!
For D: "Zombie Power!!! Of course they don't play fair!"
So here yall should see that at least some part of TFP is actually listening. As for this entire situation with underground stuff... What ever TFP wants TFP gets. I think one of the TFP guys should actually stop for a minute and take a 'bigger picture' look at all of this. I 'read' some where that underground caves and such was 'a thing' before, but there were issues. But now there's talk of environment things... That would cost a lot in my guesstimation, but the ultimate question is "Is it worth it?" For me and for us - We're fine with what ever TFP wants to throw at us. We are a unit, we are a team and we are "The Badlands Crew"