I am happy to report that after two days of complaining with friendly admins, who cared enough to push the support team, and after a couple of publications such as this thread, Gate.io has adjusted the withdrawal settings. I have been succesful in withdrawing my RBTC!
The minimum is now 0.10005 RBTC (still a lot and actually too much) with a fee of 5.0E-5 RBTC.
Thanks to all responders for the support. It made me feel less alone in this matter.
I am glad to hear that they decided to lower that minimum amount and that you managed to get our your money out of there! I still don't understand why the hell they enabled depositing RBTC if they don't plan to let people trade in the near future. I mean its one thing to enable deposits few days ahead of trading, but this is something completely different and doesn't make absolutely no sense to me.