Yes, the DoT stacks. I've tested this myself and it's fairly easy to test. The explosion is a different story and should stack as well since it's based on weapon damage now, not monster health. If a monster has 4 EPs, 1 per monk, on explosion, the aoe damage should be weapon damage percentage from each monk. This one needs testing. I tried earlier today, but I failed cause I needed low damage weapons. lvl1 weapons are to low, legacy too high and I'm too bored to level up a char to 30 or something to get low damage weapons.

EP does a ton of damage even on T6. Even a legacy lvl60 weapon kills trash on EP explosion. U need to get low enough so u don't kill a pack of trash with a single monks EP. If u can get that, then go with all 4 monks and cast EP. The bleed itself from all monks should kill that single mob and make it explode. If the explosion now kills a pack, then it clearly stacks the damage. Try it a few times to make sure it was not a crit (assuming it can crit). I'll be surprised EP doesn't stack this way to be honest.

But regardless of EP explosion, monks do very good damage even without EP. Survivability is good, damage is good. U can go melee, u can go ranged, u can be mobile. Right now they are in a much better place than most classes, so why not?