Number formatting should be fixed now. You should theoretically be able to go infinitely. However I've not fully tested it.
The drawback is that in the new build progress had to be reset to allow the new systems to work correctly.
Yep, that's fine for now. It's a system for the end game but I need to find the right balance for it. It's meant to be a really powerful enemy for you to defeat as the game progresses so for now, you can imagine he's so powerful that you're barely able to hurt them :)
Glad you've gotten so far though. I've not even tested it to that extent. The numbers theoretically shouldn't break, but I have a feeling you'd be the first to find out! :P