SD card as internal not working is a problem for me too. I tried to use Link2SD but no luck. Tried all tricks on the on the internet plus unpacked and repacked the boot image many times altering fstab etc while trying to mount the second ext4 partition, but no luck. Did anyone manage to do that and use Link2SD?
Another bug I found: I have 2 sim cards (different countries) and when they're both in, mobile data does not work at all on neither of them. Tried all sorts of tricks also. Hope this can be fixed in a future update. For the moment I took out one of the sims (don't need it now) and mobile data is ok.