ArchKnight AQ GD
A lot has changed, sadly not around for Beta so I can't chip in there but I was around for Gamma and until currently.
Weapons no longer have their own stats for example...
Weapon A: 10 DEX/12 TECH
Weapon B: 8 DEX/14 TECH
It's now equal across all swords, auxes etc have their stat limit set in stone. The damage has changed via a decimal. It used to be 3 being the weakest damage, now it is 30, not sure why this happened though.
As for the PVE elements, it's a PVP game from the start. You can fight NPC's still though. There is the Legendary feature now, more is detailed here: http://epicduelwiki.com/w/Legendary_Mode
Should still be current on the Wiki but cannot guarantee it as I am not Legendary myself yet. Also to top it off.. a release log: http://epicduelwiki.com/w/Template:Release_Log