There are a few quests that will be impossible to do when you are much higher level than the quest, most noticeable is "Toxic Tolerance", which is part of a quest chain that leads to a mount reward.
There will not be given help in these cases.
So while leveling can be tough work, and your game hours are low due to work and such, consider leveling manually, since you WILL want all mounts later in game.... that's just human nature!

