Generally I try and build in places with not much line of sight, so things cant spot me from miles away and home in, garages in houses, firestations, etc are good, just between some houses at a pinch. Or just work at night with no lightsource for things to find you with. Just fixing up a partly damaged car then driving it somewhere safe to mod it is also alot easier than building from scratch.
1.) How do I deal with regular, bug-sized wolf spiders and jumping spiders? They block me from shutting doors half the time and it's extremely annoying.
I generally shoot them, they get auto targeted fine, im pretty sure throwing stuff at them would work. If in doubt, burn the building down around them.