When I was young I was stung by a scorpion that had been hiding in my dirty clothes. My father told me "This is why you should clean your room. The scorpions won't have so many places to hide." I told him that I would rather be stung by a scorpion once a year (or so) than do the ceaseless work of keeping my room clean. I feel the same about the kind of privacy concerns you are raising here.

Maybe Brave telemetry is reporting stuff I don't care about - time spent in the browser, number of tabs open, crashes, etc. Maybe Brave telemetry is secretly smuggling data I do care about and they are using that for nefarious purposes. I would rather deal with occasionally being stung by the latter than spend my time worrying about it and restricting myself to open source, carefully audited, minimal risk tools.

As far as impersonating people to sell their products, I don't really know what you mean. I'm guessing it's something about them creating profiles to receive BAT tokens on their behalf until such time as those people joined the Brave ecosystem (if they do). I see this as a "growth hack" and maybe distasteful but not a deal breaker.