1. all interiors other than the default one will not spawn. i just fall into the void. the only thing there is 1 block of tnt.

2. some exteriors won't let me open the door, e.g the default, 1996

this has happened to me to

Ya same.

Well I do guess it is Buggy ,as warned.

The Dalek Mod TARDIS Exterior A works

It's a known bug by the devs already. As stated before it's release, the update is a test build that will contain bugs.

Also you should have used the bug reporting feature in-game for bugs in the tb, it was announced in the Discord.