Meh, you should really toy around a bit more with Rawr.
1) "im fairly sure rawr is just using the numbers from relative stat values."
Wrong, it is modeling each gear item based on how much an upgrade it is. If you're 1 hit rating short of being capped, it won't advise items with 100 hit rating, even if hit has the highest stat value pre cap.
2) expertise vs strenght
Expertise actually is worth more once you get raid buffs than before. It's not that hard to imagine really, when you start hitting very very hard, missing that hit costs you more than if you hit very low.
Anyway, Rawr has settings to simulate raid buffs, feel free to toy around with them. (just say off the 'bloodlust' under the 'buffs' tab, this one simulates 100% bloodlust uptime)
As for my personal opinion, I'll be using one single expertise gem to get capped in BiS gear (a few items away still

), before that, I'm just gemming strenght for stronger JoL and near equal dps.
edit: I would also advise against using alot of hit and expertise gems, as each item upgrade will mean tons and tons of regemming. (I have this in my tanking set, where I ride the 540 def cap constantly)
Another good tip is to plan your gear upgrades ahead where possible. In my case, I would have gotten a tiny bit more dps by crafting the leather boots, using a different neck and different head/shoulders on short term, but I opted to craft the mail boots a few weeks ago, simply because the Algalon boots are a direct upgrade of these, which makes it easy to plan my upgrades.