Can reinstalling Sims 3 speed up the game?

I'm playing Sims 3 on a late 2009 MBP with 3GB of RAM. I started playing on OS X Snow Leopard with 2GB of RAM and the game ran fairly fine. After I upgraded to OS X Mavericks, I have a terrible lag which won't go away whatever I try. I upgraded my RAM to 3GB and still no improvements.

I think the Mavericks update caused my problem: first of, the system uses significantly more memory than Snow Leopard. Moreover, I just updated the system, didn't do a clean install. Even with more RAM, didn't get any faster (the system is now fine).

My major problem is, I can only play in a tiny little world, otherwise the lag is unbearable. CAS is still a pain in the ass: I have to wait literally MINUTES for items to load. For example, if I create a sim and click on clothes, I have to wait till the specific sets of clothes load up and till that I cannot do anything (sims don't even blink during that time), even clicking to a different category. Let's say I picked a shirt (after like three minutes of loading), if I click on another category (eg. trousers), I have to do this waiting game all over again (and yes, if I want to go back to shirts, even though that set of items had been loaded up before, I have to wait the same time again).

I don't think it's because the CCs I have. None of the files are corrupt (I checked) and I don't have an insanely big amount of CC. Actually, nearly the same amount was running fine on OS X Snow Leopard.

So, my question is: if I reinstall my game and expansion packs, will it make run faster? I'm also putting back all of my CC – it would take ages to redownload everything and some of the creations are no longer available, so I really need them. I have the base game and five EPs, so it would take quite some time to reinstall. (And I'm always scared of anything going wrong.)

Anyway, I'm reinstalling. However, the installation guides are a but confusing. This one says after installing the base game, I have to apply the patch, then install EPs, apply patch again, then apply the crack. While the installation guide that comes with the ultimate fix says I have to apply cracks after the base game and after every single expansion packs and patch at the very end.
So, when exactly do I need to patch and crack?