Frankly, if you have the hard drive space, you're much better off to use Bootcamp and play under Windows. Aspyr's ineptitude and quality control makes even Eaxis look like a gift unto gamers and at least then you can play Freetime, Apartment Life and the additional stuff packs now instead of sometime in 2010.
That said: I remember some weirdness with existing cracks not running properly under Leopard. You may want to hunt out Leopard specific cracks and instructions. You may also want to try running your existing cracks as root using
Pseudo. Basically it lets you easily run any gui app as root -- this does have some risks but, hey, so goes life.
Edit: It may be helpful to tell us exactly what you've downloaded. FIve packs would proably mean up through Seasons, no? If so, you may want to arr up a copy of BV. BV was released post Leopard so any cracks would likely be Leopard compatible.