Making no place safe whatsoever will be the end of this game for me.
If being killed and having your base demolished in every single thinkable circumstance is where this game is headed, ill be out early.
Zombies digging to bedrock? Thats absurdity just a little too far. Or spawning there with literally no way in? Come on.
Punching (yes with hands of rotten flesh and bone) through steel reinforced set concrete is already ridiculous.
If digging digging zombies are a thing then I will say one thing, in order to at lesst save some of the community id seriously hope its an option that would be part if a hardcore no escape mode and able to be turned off.
You cant live underground without having to surface anyway, and you cant grow crops there, you need to leave to loot and those killing zombied need to surface to fight. Why cant those restrictions be enough.
Just like its been said by those of limited diplomatic ability, if you dont like underground bases then dont make them.
I have a sneaking suspicion that its these people that play multiplayer and get so annoyed that they cant find underground bases that they think noone should have safe refuge below ground.
Balance. Balance. Balance!
Anyone that thinks any of these proposed changes mean being killed and having your base demolished in every single thinkable circumstance is assuming TFP will be
completely negligent in balancing new features. I don't know why anyone would make that assumption. I bet it sounded scary when it was revealed the Blood Moon horde would change to be infinite, spawning an endless number of zombies until morning. In practice, it turned out as a trickle of one or two nuisance zombies.
Did we just get lucky? No! The designers did their job, balancing game stages and more, so that while the new feature
could have been set to make things horrible, it was set reasonably to make things better.
Regarding digger zombies and Swiss cheese, the same thing applies. If all zombies spat acid, they'd turn your walls into Swiss cheese. But that's not what usually happens, because the developers harnessed the acid-spitting feature in a more intelligent, limited way, reserving it for one type of zombie. Similarly, if all zombies could dig, we would (and did) get Swiss cheese. But if, say, only the miner zombie digs down, you'll only get a few holes to plug per horde night. Why is that so bad? It would be sufficient to change up underground gameplay, because all the other zombies can use the same hole.
Regarding radiation that rises underground on horde night, that seems like an improvement on Jackelmyer's original idea to raise the water level, since it can handle terrain of variable height. It's a pretty brute force method, though. I would prefer a method that directly involves zombies, the reason being that zombies are the main antagonists. Fighting zombies is the most developed part of the game, and it would take a lot of work to flesh out substitute gameplay that was as developed.
However, making radioactive... stuff a valuable resource you can collect would help in another area: the risk versus reward of killing tougher zombies. The valuable stuff we have now - brass, magnum parts, electronic components, rare ores - only makes sense in certain places, which means some enemies (bears, for one) don't offer anything to make killing them worthwhile. If irradiated zombies could be harvested for units of a valuable made up material, it would be a reason to go after them.
Why would granite need to float? Who said it floats? Is there no way at all to counter that exploit? Seems like you could come up with something. I thought that SI was a check to find the max number of blocks that could be placed horizontally on a support column. If that column doesn't have an unbroken chain straight down to bedrock then the blocks fall. Gaps make it so what someone thinks is a support column is not really a support column. So just because we make the check extend to granite that wouldn't negate gravity below that point would it? I'm not advocating for "no gravity below granite" so I'm trying to figure out why the granite slab would just float if it isn't connected to anything.
Of course we have current floating base issues that haven't been solved yet so perhaps floating bases amounts to Pimp kryptonite and Gazz just knows they'll be powerless to stop it....
I am totally playing devil's advocate here, but...
You defined it such that SI isn't calculated under the granite layer. That means whatever's under the granite layer doesn't affect its SI: since no calculation is performed, the granite's SI is defined to be 'okay' no matter what. Once you have that, you can pick a patch of granite, and dig out all the stone underneath it down to bedrock if you like. The granite will be unaffected. Then dig out a perimeter on all sides of the granite patch, and you have yourself a solid tower of dirt with a granite floor, which is unattached to anything on any side. Replace the dirt with whatever you want, and you have a floating castle. There may be counters to the exploit, but you'd have to define what the expected result is.