NXT does need a mid card title. The NXT United States Championship would a good way to do that. There's a lot of talent in NXT that do not get a lot of TV time, especially given the fact that NXT only airs for 52 hours a year, plus 5 lots of 2 hour specials, so a total of 62 hours a year. There's a lot of talent that aren't in the running for the NXT Championship, but an NXT US title would give them something to fight for.
As for two hour editions of NXT, they do have the roster depth to sustain it, but I think it would be better to have more 2 hour NXT TakeOvers rather than 2 hour NXTs for the moment. I have no idea how that would happen currently, but that's what I would like to see.