WW bleed, Claws, Relequen are all dots (PvE perspective). Also higher HP, less dot dmg taken and with higher resistances makes you less squishy than most DPS.
Bone armor that pulls on a WW, even while temporary, is great for PVP.
If you have to have the Necro abilities slotted- and you have all werewolf abilities slotted while in WW form- will you actually get the buffs?
No. Passives that require you to use an ability or have one slotted on your active bar do not transfer to werewolf form, which is why there the few passives that do carry over are important.