1) Not gonna lie, mostly got the interchangeable bowls/jars idea from Valmod. In some cases, yes you do need to have 2 different kinds because it makes more sense to use a bowl in the crafting (and give it back to the player if possible) than using a jar. I'm pretty sure eating clay is healthier than eating glass.
As for the cans, I put that quest in because there's no use for cans once you have a cooking pot, other than oil (which I think I changed to using jars ANYWAY) and scrapping them. That way you can use them to get a reward.
2) Ferals only run around in daytime for approx 1-2 hours. That's how the game handles the "refresh" of spawning. Nothing I can do about that and the point of night time is that it's supposed to be dangerous. So I either get rid of the ferals (not happening) or play around with the spawn rates (Which means more zombies in general). The rad zombies I already turned DOWN once on the spawn rate, and yes, you can totally kill them with a level 100 bow, even with health regen. I've done it with a level 50 bow on Warrior, at level 5 and I only have 1,400 hours. Headshots totally matter.
Side-note: That's also why I had to change rad zombie loot because I had an AK-47 with 50 bullets on day 1.
3) Aware of this and currently playing with the spawn rates.
4) Didn't know about that... well I knew about the stone axe scrapping to give you 1 stone (when 1 stone makes 2 sharp rocks), but I figured if people really want to dupe stone then they must be SUPER desperate.
5) Classes.... oh boy. All I'm gonna say is this.
It's not getting changed. You can make class papers for half the cost in a writing desk. There's other mods out there where you need 200 OR MORE of their equivalent of skill notes to make a new class. Part of the point is to try and ensure players have other goals to pursue at higher levels as well. Lowering the cost would negate that.