> If I open source it then anyone could just take it and rebrand it and pretend it's theirs.
Not necessarily. Depends on what license you use for the code, but if it's not a copyleft license they can't even create a (legal) copy if you maintain copyright and don't give anyone a license to copy the code.
It's probably less about legal forks and more about bad actors forking it, inserting spyware, and buying Google ads against "vpn server" and "tunsafe". It seems like it's more of a problem for open source software targeting nontechnical users, and I imagine uTorrent had a lot of issues with it.
I can see that angle. We're all used to curated packages from distro maintainers, whereas Windows software is like the wild West, especially for those not so technically competent.
Not necessarily. Depends on what license you use for the code, but if it's not a copyleft license they can't even create a (legal) copy if you maintain copyright and don't give anyone a license to copy the code.