If you see my old posts, you'll see that I had this exact concern.

I have since learnt that pulling a DDoS attack is actually quite resource intensive / expensive to the deployer as well, and unless you believe that you are being targeted because of something very valuable you host or that you have a technically inclined enemy who is specifically out to get you, you should be fine. Have a good think about your threat model.

With regard to bots, scrapers and the likes, yes, they are a real pain. That can be tackled with Anubis + BadBotBlocker + Fail2Ban + some custom rate limits.

I assume you are a lot more experienced than me based on the number of things you have listed to have self hosted. I feel a well configured reverse proxy with the tools I suggested will take care of 95% of all your not and scraper related worries.