A bit of a late reply, sorry…
So far as I can tell, eDeath Decap + Faith merc is the absolute highest DPS build there is for a Fury Druid and isn’t any less safe than any other 2-hand weapon. I checked all eBotD bases (bows/xbows can’t be eth sadly), Grief PB, Eth Tomb Reaver, and Eth Reaper’s.
I’m running an eDeath Decap fury druid, and even without Faith, Might, and Pride (so only HoW), he kills most non-act bosses/phys immunes in 1-2 hits, 3 if you’re unlucky and roll near min damage repeatedly. He also has a 240% eth Zod Reaper, and that definitely is slower to kill. While, yes, on paper Reaper does more dps against a 50% phys res monster than eDeath Decap, in practice it’s slower. If Reaper can kill before it procs Decrep, eDeath Decap will kill faster. Reaper + Might + Pride is 20 frame fury and eDeath Decap + Faith is 19. If Reaper kills on next hit after proccing Decrep, then at best that’s 2 hits or on average 4 hits (33% proc chance). eDeath Decap will kill nearly every P1 non-boss/act boss in 1-2 hits. If it is a boss/act boss, eDeath Decap has Reaper/Lacerator on swap, so Reaper alone has no benefit over eDeath Decap. This isn’t even mentioning the significantly higher CB/s (Crushing Blows per second) eDeath offers over everything else. Just to give an idea, 19 frame fury eDeath build is 4.25 CB/s and 24 frame eDeath is 3.38 CB/s. 20 frame Reaper is 0.93 CB/s and 18 frame Reaper is 1.03 CB/s.
Even without any merc, eDeath Decap does a lot of dps (130K+) and kills plenty fast. Obviously not as fast as adding in Might + Pride or Faith, but extremely respectable. Really, any good eBotD, eDeath, eth Reaper’s, eth Tomb Reaver will do extremely well. eDeath is notable for only needing Vex Gul, having a convenient 5os max base that is also its highest dps base, having the highest dps overall (if you really care), and having incredibly high CB. Adding in Faith does add Ohm Jah, and Pride adds Cham Sur Lo, but almost every fury build wants one of them in the end. Those that don’t will ask for nice eth Reaper which isn’t cheap.
Rough dps numbers, using same near perfect gear + perfect ED/IAS rolls + lvl 91
Grief PB + Stormshield + 30max jewel = ~87K
Grief PB + Phoenix = ~101K
eBotD Archon = ~101K
eBotD GThresh = ~111K
eTomb Reaver ZodLoLo = ~113K (beats Zod+80/30, ZodLoOhm, and ZodOhmOhm)
eBotD Tmaul = ~117K
eDeath S-E Axe = ~117K
eBotD GPA = ~118K
eBotD Archon + Faith = ~128K
eDeath Decap = ~135K
eReaper + Faith = ~152K*
eReaper + Might + Pride = ~165K*
eDeath Decap + Might + Pride = ~170K
eDeath S-E Axe + Faith = ~171K
eBotD Tmaul + Faith = ~173K
eDeath Decap + Faith = ~179K
*Assumes decrep is active and adds 50% to the final dps number. In reality, it would add more depending on the monster’s phys res, but for reasons mentioned above I left this at 50% for simplicity since it ultimately doesn’t matter enough to get specific.