My basic thing was Taurog with Alchemist pact. That equipment isn't so much a problem for a Tinker. CYDSTEPP + WEYTWUT (placing them beside the right wall so I could use the holes there to prevent walls) was how I got the extra strikes I needed to hunt things. I did fireball the bosses a few times... but I basically had a tonne of melee damage and death protections to do the real work. That, and all those potions from the sub-dungeon right at the start... I accidentally level catapulted on one boss.
EDIT: And I did get top XP on that run with a measly 270.