Yeah, I saw the other thread after reporting the bug, the problems seem familiar. I think the third problem is also related to the first and second one. I ran into problem 3 by this steps:

I ran into the same problems in Blender 2.8 Beta on Mac OS. I found out that the changes can be updated in the viewport by hitting undo, so perform a change in a material node twice and then hit undo once. It doesn't solve the problem, but it works.
Would be nice to have a stable 2.8 version for Mac soon :)