While I agree with most of the things you said, half of these only apply to people who take their time getting to level 60 on their first jobs. This won't work for people who want to rush to 60 in 2-3 days. For your first class to 60, if you decide to level it all the way in one weekend, you will eat up all the MSQ and side quest and will have to grind dungeons / fates for half your level for both level 58 and 59. What you said does work for alts though. I like to do all the roulette and challenge log every day / week to maximize the bonuses.
And they definately need to add XP to the level 50 dungeons. Otherwise the only dungeons you have to level from 50 to 51 is Aurum vale and that place is horrible due to the quality of players that runs it, and you would have already ran it a bunch of times level 47 to 50 (unless you grind fates and stuff).