1st things 1st, you should post a detailed breakdown of your build. How many points in STR and INT with no equipment, what your skill trees look like, what weapon you would like to end up using. That would give a good idea of where we should steer you.
Quite honestly, i was in a similar boat to yourself with my skills all over the board. I have since fixed that with cursed hearts and am working on farming at 64 with a 9 lvl gap.
Farming at 56 i dont think would be bad at all, i did a bit of it myself at that level. Penons are prolly what you would wanna kill at that lvl with a decent weapon, or a high enough magic balance to 1 or 2 nuke them.
What i think you should start with right now is lvling. Keep yourself at a 0 or 1 lvl gap by ONLY lvling your highest mastery, not the skills. Keep doing this till you are at 56, then if it is available to you, use the potions from the item mall to get rid of the top 5 lvls of that mastery (so you will gain 100% of the sp back on the lvls you spent the most on) then gather 40 cursed hearts to get rid of the remaining 4 lvls of that mastery to put yourself at a 9 lvl gap at 56.
Once there, the fun begins, lol. Keep the cursed hearts quest while you are farming to clean up the unwanted skills that you have, and kill kill kill until you get your main masteries where you want them. If your going to be a nuker, i would suggest farming enough to get all your main masteries to 50 (for the 2nd nuke) and if you take fire, high enough to get that to the 3rd book.
Well, im not gonna read over what i just wrote, cause i think i jumped a bit overboard with the length, so you can just read this and ask anymore questions that you may have.
delving from lvl 70 to the lvl 20s is easy 
, heard of murdering? 
