Some addons won't work!

Hello, I recently started playing TBC again in Warmane with some friends, I downloaded all addons and stuff I need and everything seemed to work just fine (except that my 70 mage got deleted for some reason). However, we were really hyped to play the good old WoTLK... And here comes the pain - I downloaded the "new" WoD models client from Warmane and I thought my addons got bugged because of it. So I reinstalled WoW 2 times, then finally got tired of it and downloaded the old client. There are like 12 addons I wanna use, but I am able to use just 5 like now. The addons I wanna use are: Quartz, XPerl, TidyPlates, NiceDamage, Recount, DBM, Gatherer, OmniCC, Bagnon, Postal, GearScore Lite and Interrupt Bar.
The addons that are currently working are: Quartz, TidyPlates, NiceDamage, GearScore Lite and Interrupt Bar.
Whenever I turn on XPerl and Quartz at the same time, NONE of these work, but when I turn the one without the other, it seems to work just fine.
I also spent a lot of time trying to figure out how to make my video settings save after I exit the game ( got that fixed somehow ).
So basicly I wanna know - why in TBC all addons above are working perfectly together, but in WoTLK just a few work together? I also downloaded multiple versions of the addons to try them out, but still none worked. If you could give me some advise on how to make all the addons work, I'd really appreciate it!
(Also my Shammy in WoTLK who was geared af got deleted, but I don't really mind it...) And on that shammy every of these addons worked fine...
*sorry for the bad explanation*