I don't see how you could do "The Gauntlet" solo...
Dunno, i guess you'd bring in your party members since you wouldn't be fighting. And i'm sure its possible to kill that many members of your party you end up with less than 4...
You could possibly spend an eternity laying traps and glyphs and stuff, but my god it would melt your brain doing stuff like that for the the entire game
Well Glyphs no, they wear of fairly quickly. Traps i imagine you could but given the buffs of the Arcane Warrior i wouldn't be surprised if you could just waste them all by standing in your own Blizzard or something while you attack.