Tor is not illegal. Usage of Tor is not illegal. If you have such fears you are either unreasonably paranoid in this regard or you are correct in your fears and you are already living in a totalitarian surveillance state that uses fear and intimidation to deny you your rights and freedoms.
I live in Germany and torrent all day (with a VPN), use tor all day and shitpost on the internet as much as time permits. I will not yield in that regard and neither should you.
> 1. If you're threat model is surveillance state, are things like this helpful or harmful?
It depends. The most useful usage for tor is to work around blocks and nation state firewalls. My traffic almost universally exits in Germany or the Netherlands where you can access any website you want from. If you life in china you might not be able to visit all the sites you want, i.e. https://en.wikipedia.org/wiki/1989_Tiananmen_Square_protests...
> 2. If you need a tool like this, what's the best way to obtain/install this anonymously? Depends: Do you have access to some form of internet connection thats not directly linked to your identity? Because downloading and using tor from your home connection if you are worried about "sending a beacon" really is pointless. A public wifi is propably the easiest way to get it.