There are actually way more, but you need testflight to use them.
There’s one exception: wefwef.app which you can just add as a webapp.
Admin abuse: yea, but unlike reddit you can just move to another instance.
Reposting: you don’t have to subscribe to all communities. And you can block communities if you don’t want to see them in your local or all tab.
Privacy: depends on which instance you choose. Do your research.
Server: I am not sure about this, but I think the server strain is placed on the subs who generate the most content / have the most users. More users means more potential for donations, which means the devs can buy better servers.
Lawsuits are expensive, and large companies can afford the best lawyers, while the government often can’t.