I haven't activated a premium account yet and I just reached my 60th building. I would like to know if the extra buildings (61-100) will not be hidden if I get a premium account and it expires.
Also, just in case it would be hidden after premium expires, would there be any chance that we can buy permanent additional building slots with coins?

P.S Question:
Is there any way we can increase the maximum rack quantity in the in-game stores?