I play both Summonerand Scholar, and what I do is that I'm a Summoner for whenever I have to do anything solo [story quests, side quests, farming for mats] and I'm a Scholar for parties. This does admittedly mean that I have somewhat less experience as a Scholar, but I try to address this by doing guild hests and dungeons even when I don't need to in order to get more practice.
Since I do this mainly for practice and not exp, the low exp doesn't bother me as much, but I'd welcome a buff to dungeon and guild hest exp.

I'd ideally like for the new jobs they make for the current classes to have different roles compared to the roles of the current jobs, like how Arcanist branches off to both DPS and healer. Having a class branch off to one DPS and another DPS would be, well, boring, and this might even encourage people to try out tanking and healing. It would also mean that you'd have different options during partying and soloing, and variety is a good thing.