Exploration level works more or less the same than normal levels. They are calculated independently however, allowing you to get more AP each rebirth. The max level is 100 and exploration 30, though both are rather time consuming to reach.
If you haven,t done so already, I recommend you join the guild Fjallheim. The stone that allows you to send an application is in Cobh/Cohb (forgot). There are often people around and most would be glad to help whenever you want with pretty much whatever you need help with.
For leveling, commerce would probably be your best bet, assuming you can hook up with some other guildies to handle the baddies (Ibid loves them baddies
) It's a bit slow early on, but once you get wagon, it speeds up considerably. It's also a good way to make money, so that's two birds with one stone.
Edit: Oh! On a unrelated note, I've experience the joy of cloning ingots last saturday. Starting with 12 arat crystals and HW and a bit of metal conversion, I turned 1 iron ingot into 2 full stacks, 1 stack of copper and about 30 silver. Mabi laughs at the laws of physics. So, I plan to work a bit more on Kyu's synth skill (78% success rate cloning silver on saturday, could be better) and get back into commerce a bit to buy arat here and there. All this and more after I get at least r3 weaving on Don. "More" including going back to Blacksmithing too.
Also, our last attempt in Peaca went relatively well. There's been a few deaths, plenty of role confusion, a bit of Oops and ensuing Fun, but overall it was a good run. It must be repeated in the future.