About priest gear

Now that I haven't got much to do with Netcownt, I decided to gear up and play Tarithel as a shadow priest, not only for dualboxing, but as the main player.
I've noticed a few things.

1) Class unbalance.

With a lock, I needed full-gem,full-enchant, blue/blue heroic gear and tuned pve speccs to reach 1800 dps and needed 80 epics to cross the 2000 dps mark.

With a shadow priest, I use unenchanted, green gemmed, 80 normal or pre-80 blue gear, with 2 70 epic items (Whitemend set) and I can easily achieve 1800 dps on the same targets.

You what's going on ? I know of course, classes are totally unbalanced, as I suspected. Not only lock vs mage (pure dps vs pure dps) but also lock vs ShadPriest (pure dps vs hybrid). Bunch of idiots.

2) DPS scaling

I talked about the Whitemend set. Yes, ofc it was a healing gear, trousers and hat. Each item has 2 gems, so plenty of spell power to enchant. And... it has a set buff, called "Increases Spell Power by 10% of your "total" Intellect".

You know where this is going... A very poor mana 80 clothie has about 800 INT. That translates in 80 Spell power, it's an insane buff that scales with your 80 gear amazingly well, as well as with mages, palas with BoK, any thing that buffs INT in a party or raid. With food or pots, it gives over 100 spell power, which is the same as a lvl 80 25-raid trinket! HA !

Today, I got my T7.5 trousers from VoA-25, gemmed it, enchanted it, and replaced my 70 set with it and a 78 blue hat.. and guess what ?

I LOST 10 Spell Power ! Yes. You heard it right. An epic 70 set matches a Tier 7.5 item and an 78 blue and actually scales better. It looses a few intellect (and crit) but then again, a shadow priest's mana pool scales with its damage not with his mana pool.
(If I have blue gems on the 70 epics, the loss will be more than 30 SP !!!)