For now, I decided to take the 87 dwarf on a trip to the underworld to test the waters (on platinum *dramatic music!!!!*). I believe I've heard the underworld beastmobs are quite hearty/dangerous but so far I've made it to the fungus village. Without pursuing my cannon skills I'd have been up the creek right now, as I've been leaning heavily before platinum on Thain's axe / self buffs / hard hit super combos, but these mofakas aren't interested in melee damage too often, flamethrower / mortar so far has kept things from murdering my face so far.
Regarding trade, its a tricky beast and I'm curious to see what it looks like around level 100 (I think platinum has a level cap of 180). The only tricky part about trade being that the difference between level and Tradeskill level shrinking affects items. Sometimes tho, I think going too high makes the game give you affixes IT thinks are good instead of ones that you think are good (looking at you, Additional potions). I have a feeling I'm going to get a reality check in the underworld and run back to the normal campaign for some levels and trading as the monsters start outleveling me majorly =p (currently fighting level 110-113+ level beastmobs but flamethrower still works for now, but dang they are starting to hit hard :^)