So first of all I do understand that the enchants needed some fixing (yes I have an enchant procing build on a character as well, so I know they are strong and a bit too OP in non-CP campains), but I realy dont like what you think this is the rigth way to fix it.

With those changes you are removing possible weapons setup because if you need the enchant for extra sustain or for weapon buff enchant you will not be able to run Duelwield/Duelwield, One Hand and Shield/ One hand and Shield or Duelwield/One Hand and Shield.
And worst of all the one hand and shield style of figthing in PvP will only be possible if your off-bar weapon is two-handed.
For me thats just turning the tables around. Before we had two weapon setups being stronger because of set bonuses etc. and now we will have two-handed weapons being the superior weapons because you have more possibilitys (taking the new enchant system in to work) then you have on DueldWield and One hand and shield..... removing the posibility of fun setup up's is just a bad way to fix a problem.

I would suggest that the changes should be ether:
1. Make it so enchantment bonus on all weapons are full enchants and that the enchant on main hand weapon is the only enchant that can proc. So no matter what the enchant is on the off-hand, it will only be used if you swicth it to main hand insted (have a red text on the weapons enchant if put in the off-hand that says "this will not be used on the off-hand weapon" when you look at the character item screen). Then you can still have the same benefit as other weapons and it will not be over powered comparet to other.
2. Make it so only damage portion of enchants are halved on DuelWield and One hand and shield. So you still can get the full effect of weapon buff or recovery enchants.