"Also, when you get Level 50, do the Main Scenario Roulette (once per day) once you've unlocked it."

That's a sure fire way to get someone to quit the game due to burnout.

Usually the latest dungeons available of the previous level cap will give a bunch of poetics. For example Baelsars wall and Sohm Al Hard give 100 poetics past level 60, plus smaller amounts for the individual bosses, and potentionally newbie bonus.
So things like Keeper of the Lake should give a fair amount at level 60 too.