So what really bothered you wasnt the story but rather the leveling of classes?

I do understand your wish of a fresh start and I am fully aware that its your choice after all, but maybe you could consider buying the level jump potion instead of the story skip one and actually play through the HW-story?
If you actually enjoy seeing the story it would be a shame to miss out on it...

PotD is a fast way of leveling btw. Daily Beast Tribe quests give a very decent chunk of exp aswell - the weekly challenge log gives a certain amount of exp aswell.
And to be honest: at the end of the day after the story is done this game is one big grind - if you dont enjoy that, I'm not sure what this game can give you once the story is done...?
Again, in the end its your choice, but if you care about the story, I would reconsider skipping it, even though I understand your situation and wish for a fresh start.