I wouldn't worry too much about gear until you start getting towards endgame stuff, or at least until Northrend when really decent gear starts dropping.
But yes, Spellpower is your most important stat in general. Hit, haste, spirit, and crit are all important as well. Stamina & Intellect just kind of show up on gear and you don't really need to go out of your way to worry about it.
I guess while leveling the thing to note is that some staves, daggers, swords, etc. are good 'lock stuff and some aren't. You don't want the ones with agility, strength or any of that garbage. Those are melee-class weapons, not caster weapons. Staff with SP & INT? good. Staff with STR & STAM? no good.
Just checked the armory and see you have a BoA staff so I'm guessing you generally know what you're doing.
Ya, some of your gear is a bit outdated for your level (I see a 23 and some 32's) but that happens while leveling it seems. Personally I don't think it's a big deal if you can go on about leveling without having many problems. Like somebody else said, if you feel like you're struggling a bit then try and hit up some instances or bite the cost and buy an upgrade piece. Usually though, just going through quest cahins will get you 95% of what you need to stay current.