Capped [Class] =/= Capped [Job]

[darkstarpoet1]

I would expect you to have to be on the Job while doing those quests. Now, bear in mind the jobs are not meant to be successful in solo play.

I imagine the quest tasks being more about completing certain objectives on the job, rather than a simple fight. If it becomes more like that then the quests will be much more interesting than a simple 'rip through it on your lv50' endeavor.

Examples:

Paladin: Survive for X minutes.
WHM: Keep an ally alive for Y minutes.

Another possibility is having the quest difficulty scale based on the actual level of the player entering.

yes, i hope they scale the difficulty to the level of your character, but i doubt it will happen. i do agree to do the quest to get the abilities and gear you will more than likely have to be on the job that it is for like getting your guild marks.

Correct, so we now know:

Unlock a Job at R30 via quest.
Job Level = Class Level
EXP is shared between the two, essentially meaning it is still the same class but containing Job Perks
To gain job specific abilities/and gear, you will have to complete a quest every 5 levels, starting at Level 30.

yes, to the extent things have been explained you are completely correct.