So, I apologise in advance if some of this has been commented on or brought to your attention.
I completed my transfer of two characters two Frostwolf from Neltharion. One I coined up to 85, the other I quested/grinded to 85 before the transfer. Both of them had problems with their transfer. First, the professions. I was pretty far along in mining with one of the characters. The other, not as far. But both of them could not mine when I attempted it. When I would try to mine copper, it kept giving me the error that it "Requires Mining". So, I went to try to relearn mining. The first time, I just relearned it altogether, without paying attention. With the second character, I saw that I might be able to just relearn the skills within the Mining profession. So I tried that and it didn't work. After rel-learning all the skills it let me, I went back, tried copper, and it gave me the same error. So I had to unlearn mining altogether again, this time having wasted the gold to relearn the skills only to have to re-re-learn them once my mining was back up to snuff to do so. And my partner had the same problem with Enchanting as well when she transferred her Shammie.
One other thing I am noticing that I doubt was intended. I am seeing that my characters that never had mounts in Frostwolf are suddenly able to use mounts (as long as they are level 20 or higher) that one of my characters had before he transferred from Neltharion. He had some 30 plus mounts, including swift, flying, and swift flying mounts. I have a level 18 druid that can't use them but has them on his mounts list. I have a level 30 monk that can use all of them. And, I have a level 20 priest that can use my Great Elekks, Swiftsabers, and Swift Rams. Also, she can mount and ground-ride flying mounts. She just cannot fly.