The annoyance of ignorance

I don't like not knowing things, especially about a class which I play. I'm refering to my warlock in particular. Things used to be fairly simple:
Hit cap: Good, varies with spec
Spirit: Lol
Intellect: Nice to have, but it didn't strike me as something to chase
Spell damage: GOOD!
Spell crit: GOOD! Except for affliction in which case it was just good since DoTs were complemented by shadow bolt spam
Stamina: Mana pool and due to the many nerfs to fear; the only thing in the way of sudden death
Agility/Strength/AP: Lol
Haste: Never heard of it
Spell Penetration: Lol

Now it's all a mess! Spirit is increasing our spell power and the speed of life tap. Both are DPS boosts (higher damage vs. lower 'downtime' in DPS spam). How good is it compared to other stats? From what I can tell it's not quite a warlock stat, it's nice to have, but not something to chase, so stop rolling on healer trinkets. Stamina is still clearly useful, more now in fact, due to the constant health regen on fel armor. Melee stats are clearly bad. Did int change? There is the spirit regen interaction, but we don't use spirit directly for regen. Crit: Good. Hit: No clue, this seems to change all the time. While leveling it seems pretty marginal. Haste: Faster DoTs, faster drains, faster nukes, lower GCD (faster DoT aplication, faster lifetapping). But it also means a corresponding higher mana cost. Is mana an issue?

What's a warlock to do!?

Oh sure, I could check a strategy guide, but what fun is that?

On a related subject, I've decided I will intentionally go against prevailing wisdom and not stack strength exclusively for ret. I will get the hit cap, or close if gear doesn't add up quite perfectly. I will get hybrid gems in yellow sockets. Blue sockets I will weep over for their crappiness, depending on the bonus.

And on a totally unrelated subject: instance grinding with rested XP and 10% shoulders is pretty fast and lets me save quests for gold.