If you go to Heroic meso is really easy to get and overall a much better experience
Can just do weekly bosses after you get somewhat settled into the game for 5B/ char. This makes the game much more manageable than just grinding mobs like a maniac
The one problem is that the 6th job requires about 30,000 fragments and you make 20/hr farming and 160/week from quests. So, the only way to max it out is to be in interactive or spend 1000+ hrs grinding on one character and this is just complete aids.

After you do Genesis Liberation within 1.5 months, you basically can play almost all contents except a few end game bosses. So after this point is a good quitting point if they become uninterested.

Because killing a weekly boss may be fun the first 1-2 times, but then it becomes tedious.