Rust is actually rather slow, those red numbers are just really scary. I almost never craft minor things for upkeep of skill levels, opting instead using those red numbers to incentivize leveling up again, crafting something that has the potential to be useful.
@ Gauth In my opinion, experimental. Pick up the CDDA launcher someone made, it will simplify everything, and make updating painless. Static spawn means no new enemies will spawn where you have cleared, but as long as it is in the reality bubble, it is possible for any critters along the edge to wander in, or follow you. If you are worried about not being able to use your defenses, turn on wander spawn, and check the overmap now and then. Or make lots of noise once its on. Which will make hordes spawn in.
Settings you will probably want to play with are Spawn rate scaling factor, Item spawn progression, enemy progression, Spawn rate progression, NPC spawn rate scaling factor, and Monster evolution scaling factor
Spawn Rate Scaling Factor: Changes how dense monsters are. I run it 1.0 right now, I think I might turn that up before I mess with mob progression.
Item spawn progression: changes how dense the loot is. I started a new game and am running it at .75, but will probably quickly have it back down to .50 then .25 before long
NPC Spawn Rate Scaling Factor: Changes how many/ how often NPC’s spawn. I recommend keeping it VERY low. I’m running mine at .2 right now, should probably be lower. Just don’t forget to check the map on occasion.
Monster Evolution Scaling Factor: Changes how fast monsters evolve, for starters, I recommend keeping it very low so your not rushed to keep up with the progression from regular zombies to hulk, brutes, and other high tier zombies, and instead adjusting spawn rates, and turning on wandering spawns to up difficulty.
FOR MONSTER EVO, BIGGER = SLOWER So I run mine at 4.0 right now, might actually up it further to make more room for upping monster density.