While playing, here's some things I've noticed (don't know if others have posted about any of these, haven't had the chance to read many of the comments)
The dragons, if there is Anything above them, no matter the height difference, they will not fly.
If they can't fly, they jump instead. Ex: I have a 13x13 hole in the middle of one of my buildings (originally meant to let dragons fly up the middle) Instead of flying up they jump (could be the aforementioned problem and/or not a big enough hole cause of their massive wingspan). What happens is when spacebar is pressed they surge upwards at a faster speed then flight, and keep going, when spacebar is released they drop at the same rate, you can still go forwards or backwards, but to keep them at the desired height you have to keep pressing and releasing the spacebar (think Flappy Birds).
Nametags, when used name them, true, but the next time the world is loaded, the names disappear.
And then finally, sitting seems to be hit of miss, in that it feels like I'm playing 'red light-green light' with them. Meaning they sit when I use the bone on them, but when I go a distance aways (not sure of the exact distance) they get up and start walking around again. When I approach they sit back down, but I have to get quite close to get them to do so.
I'm playing this in 1.10.2, with the recommended forge version. I haven't played with it on survival yet. So some of it might be only in creative.
Some of this may be intended, but these are things I've noticed.
I've been having the same bugs. The "dragon-jumping" thing doesn't really happen with me all the time, but sometimes it does. I'm not sure exactly how it happens. Also the nametag thing happens after I simply leave the location and come back later. Everyhting happens both in creative and survival mode