Trust them to do what? Trust them with what?
If you're using plain HTTP, someone can MITM in HTTP, and a rogue authority can issue a certificate to someone who isn't you. This is not an argument against you using HTTPS at all.
Self-signed HTTPS would be even better, but it seems to be frowned-upon by browsers these days.
Absolutely not. I am pointing out that even within your (incorrect) assumption, you using HTTPS does not hurt your security at all.
That you take it to mean "HTTPS is insecure" is your own assumption, that you take it to mean "equally as insecure as HTTP" is something you made up.
A parallel: A lot of companies make seatbelts, you're not sure you can trust all of them. Even though they would be caught by quality testing and instantly go under, it is possible that one of them would build them with cheap materials that wouldn't offer much protection. Therefore seatbelts are not completely safe. Therefore wearing a seatbelt is equally as safe as not wearing one.