This is a total noob question but whatever. How come I can't change weapons at the Blacksmith? I've unlocked a bunch but when I go to choose them, it doesn't let me. I noticed the red numbers next to the weapons, all of which say 1 except one weapon, which says 10. I'm guessing these are the required level or something. But I'm level 21. Does it have something to do with me playing as Alien Hominid?

the little red number is the level required to wield the weapon but because you are playing as Alien Hominid, for whatever reason it doesn't show his weapon change. You might get the stats for that weapon but it will not look different than his original blaster. Im not positive but I believe that is what your problem is because I played as Alien Hominid and picked up the pitchfork on the first level but it didn't change the look. Go to the main menu and select character stats or whatever its called and scroll through to see if your Alien Hominid characters stats have changed because of the weapon effect or not. I hope that makes sense and helps you out