"You're a little bit late. 1.5 went live already."
Not for me and I'm a PCer. Steam hasn't updated me, they updated the CK but not the game. I sent in the support request. In 3 or 4 days they will get back to me with a message that I can review my question by selecting the following thread (doesn't work). Then we'll spar. Then they will send me a canned message that this is a third party game.
Reading the comments about the new crashes caused by 1.5, maybe it's a good thing.
So, how do I get the 1.5 patch? I get other patches from Steam. Maybe it's because the title of a previous support request related to their workshop subscription system screwing up my load order and crashing my game was "Is Steam a virus?" This of course was meant as humourous and to try to get them off their stick. I have even tried running the game from Steam, which says it's current (not true, still 1.427). I get news messages related to Sky Rim patches with no content.
So, I can't play the game so I'm running around (very frustrated) being a little obnoxious.
I have no idea why you wouldn't have received the update, since it should automatically load when you try to start the game. And I'm not sure how Steam Workshop could crash Skyrim, since all it does is download mods as if you'd done it manually. You can still set your own load order.
It sounds like you've made a lot of modifications to the game, and I would look at disabling mods before saying that Steam is causing the crash.
Edit: Also, there's a PC support forum.