If you want have mf, with runemaster, that will cost you some damage, more so if you crafted mf jewels, that still can have good mods besides mf.
I don't know about this build for farming, yeah you can run through fauztinville with it fairly fast, but you have to click around everywhere, for the cost of build it really isn't that good compared to what other builds/classes can achieve.
I found that procs such us in for the kill amulet increase clear speed quite a bit (also up to 50 mf from that). We have plenty of damage, lack of aoe is our main weakness for clear speed.
Su labrys proc doesn't really have that much impact on aoe clear imo, stormblast has shitty aoe, so it is mostly for extra hit vs bosses, pretty big one. But for clear aoe axe should be even better, maybe except less str bonus (non class specific items get less bonus than barb items iirc).