Hexxit Server Woes

[CiarCroi]

So first off, I just want to say that this modpack is awesome, I love it, my friends love it and we love to play together.

Which is what makes this next part so upsetting: It seems so buggy. We've had all manner of issues on our server lately. Bad chunks, missing chunks, entities being spawned in far, far too many large groups (Trust me, 1000+ beavers isn't as cute as you'd think it would be.) For an exploration server, we really can't explore. Moving too far out from our home area causes internal server errors, or we hit a bad chunk and crash, or we find a massive mob colony and crash and burn in lag. How can we prevent this kind of stuff? I'm tearing my hair out over this server and it's issues.