Self-defense is perfectly okay.
That said, the only thing I've found that's non-toxic and effective is CedarCide. There are imitations with other ingredients, but the added ingredients do nothing but add to the scent overload. CedarCide has a strong cedar scent at first, but it dissipates rapidly.
It will repel all things bitey and will kill whatever it's sprayed directly on. I use it for fleas when necessary. (I use nematodes in my yard, but my dog will pick up fleas occasionally at the park.) I have no guilt about killing mosquitoes or fleas on me or my dog. (I've already had West Nile and don't want it again.)
I've wiped it on my screens to keep no-see-ums and fruit flies out. (Spray it on a thin, soft cloth and wipe the the screens.) It works fairly well. It's an effective repellant for anything bitey and is good for humans and nonhumans.
It isn't as effective on spiders. I don't know how effective a repellent it is for spiders, but it's worth a try. I don't worry about non-venomous spiders, but I will kill the venomous ones immediately. I live very green, but I keep a bottle of Windex under my sink for when CedarCide doesn't work. I only use Windex to kill bugs. It's not nearly as toxic and long-lasting as regular bug sprays. Windex will kill any bug, anywhere, any time. It even kills our palmetto bugs (flying roaches, up to 2.5" long). Bugs are nearly immune to commercial sprays, but Windex works like magic.
My dog survived a very bad black widow bite (long, awful story) and when we found dozens of them all over the yard, only Windex killed them. (My then-bf used spider spray which seemed to feed them. I used Windex and they died instantly.) It's one of the very few chemicals in my home.
You have to weigh the pros and cons of everything. Self-defense is different from wanton violence.