Okay, I hate to say it, but we gotta be honest, these combine WAY too well, hands down. There should probably just be a limit to the number of triggers or something from a single attack!
I say that because I just triggered literally, I counted, 71 attacks off a single attack using a weapon that fires three shots which, when they crit, trigger an AE, which seem to then count as "attacks" on other targets and, thus, trigger another salvo of three shots on that target, which triggers another AE, etc. etc. They don't all even fit in one screenshot with the combat log expanded, there's a whole 'nother page.. and again this was literally from one attack, the first in the combat. I think the biggest 'trick' is that when the weapon crits it causes an AE and if THAT crits it can trigger a swift-flurry attack, which then starts it all over again with enemies in a cluster.
I mean, there's "synergy" and then there's "one attack from one character mowing down six or seven enemies at once with a basic attack in an insane endless fussilade". Seems a tiny little bit supremely excessive for certain weapons and abilities.
Also, I noticed a very annoying issue of 'spell resist/reflect' preventing things like the Alchemist's belt from summoning potions to your quickslots at the start of combat.