About being yourself... That really is the best advice to avoid rejection. The problem is that no one can tell you how to do that in a comment section.

It's likely that something in your life is out of place, making it harder to be "Yourself." You need to learn how to identify it and what to do once you have.

Therapy is great for this if that's something you'd consider. I'd be willing to give a little guidance, if therapy isn't your jam. DM me if you're interested.

I generally don't care what people think about me. They're are obvious exceptions like my employer. If you have shitty views that affect others negatively, like being a homophobe, transphobe, or a hard right conservative, then you're going to justifiably get shit on and hated on. You can choose to not care what people think, but in the real world there are consequences. If you live a life of inclusion and empathy, then most of the work is done towards not caring what others think. Basically, don't be an asshole, and if you are, keep to yourself and don't run a business. Good people don't get "canceled".

if you try you’ll push yourself into a bad mental space that many therapists make their livelihood off of! I am a big people pleaser so have had issues with over-valuing the opinions of others. One important thing I did to combat this tendency was to come up with a reasonable set of principles for myself so that I didn’t feel like I always had to take what others might think on board (because I’d given myself a reference). Another thing that helped was eliminating anxiety around things I was quite certain one shouldn’t be judged for (in the sense that some things just shouldn’t reflect on your character).

Being worried about having your job taken away and similar is a bit different. I think the things you do to prevent risking this include not voicing “hot takes” except with people you trust and who understand you, avoiding internet arguing, keeping your boundaries up at work, etc. I think most people have a pretty good sense of what ideas might be wildly unpopular in their locale.

As a slight side note, things like tenure (in the US) and anonymous review processes in academia were put in place precisely to ensure that people weren’t blackballed for theorizing things that were unpopular or that would potentially step on the toes of some politician who was threatened by your research. Many things that are popularly supported have and will continue to be wrong, so you need a certain self assurance to fall back on. Preferably your self assurance is supported by logic and reason and not dogmatism—but this entails a fair amount of hard work and study and reflection—you can’t just rely on intuition.

People often say that one should not worry about what others think of them, but life simply doesn’t work that way.

It does, but it's not all or nothing.

Take the scenarios you've outlined for example. They may be possible and you may not be able to truly proof yourself against them, but they're also very unlikely to happen to you.

So the amount of "worry" you put in to those things should be appropriate for the likelihood they're going to actually cause you issues. Which, in this instance, is "some, but not much". And if you're worrying about it more than that, then the answer genuinely is, stop worrying. Of course, that's easier said than done, but however you achieve it, that's the real goal.