If you are away from the game for a few months, you can come back with all your crystal drained. That seems excessive. Drain credits, but not crystal (which takes lots of bot hunting to gain).

+1.

Having to use several Crystals to buy a ship is already a steep limit on it's own since you can only farm 20 Crystals a day (30 if lite sub), so having to pay crystals for rent at all is kinda nuts. It's like limiting players to 200k-300k credits per day.

Agreed. +1