They control Anon downvoats. I saw about 3 weeks ago because I was up with my daughter all night. There was this potato shitposting in annon and it was equally downvoated +8-8 and when I woke up it was +8-0. It was busters I'm pretty sure. there was about 4 of the posts like that and they all did the same.
Gabara can fake ban you from any sub... fake banned me from v/Canadafirst... my own sub I freaked for a sec n tested it...
conjecture: @Needlestack was telling the truth about Anon posts. That's their playground.
On the issue of being ID'ed in an anon sub, its almost certainly not because they have some secret admin access to voat's servers.
If you don't disable subverse CSS, you load all the elements within the style sheet. If some of these elements are loaded from a server that they have admin access to, they now have your IP. They can then use metadata and some fuckery regarding the combination of elements you are allowed access to narrow your IP and match it to your username.
If you then post to an anon sub that they control (all three of the major ones) other CSS elements again leak your IP, they can simply match up your IP to your username from a list.
As for the fake bans, are you sure it wasn't a near spelling? You'll notice that Gabara only mods 9 subs, and its pretty simple to create a sub, send some bans, and revoke your ownership before anyone can check the user page.
Finally the vote manipulation... yes. They have scripts that manage accounts, and the existing javascript to auto upvote or downvote is pretty simple to modify, even for someone (like me) that can't code for shit.
In short, these all sound like tricks that any motovated sophomore working on a CS degree could manage.