I just wanted to say thank you to everyone for all of your amazing feedback and help finding remaining bugs and issues. Screen shots and video, descriptions of procedures to repro have all been incredibly helpful.
I've spent my weekend working through and sorting it all out. We will be putting up a patched version as soon as we can addressing remaining issues in the betas channel for all to try out in the coming day(s). In fact, there's a new Mac and Linux build going up AS I TYPE THIS that alleviates the black screen madness people were getting.
I deeply appreciate all the understanding, kindness and patience everyone has had so far. This is a big game, we're a small team and dealing with many different configurations on three platforms is a lot of work, so we're doing our absolute best to get through it all. (Lesson learned: launch one platform at a time :) )