You have no leverage. Again if you get the host taken away, then the operator has no reason to go back up and payout any miners. You basically will be giving them a reason to exit. Not your keys, not your coins. Sadly in mining the operator has all the leverage. Also being incorporated in Russia gives most of the miners little legal recourse right now.

If you are so pissed off, Hire a lawyer. Or wait until you finally get a payout. Those are the only option you have that make any sense. And yes the pool has another option of closing its doors and taken all our crypto, which it has not done yet. You should not force this last option, which is all you would be doing. I never said the situation does not such. I do have Eth stuck on the pool too. I'm just say the pool works for other coins again, if you have some patients we might eventually get our Eth out. A better chance than if you ruin the pool's hosting.

As to the ownership, you might be right, however, moving the corporation and changing the name does not necessarily mean the original owner/operator is not still there. Might have had to change the name to incorporate in Russia. Here I can understand your reasoning.