These graphics macros tweak even level 1 settings to be better. You will need to enable Projected Textures just below your Graphics slider, though, or you won’t see swirlies that can kill you.
And don’t disable “some” addons. Disable them ALL for testing. The ones that are slowing you down may not be the ones you think. Re-enable them one by one to see effects.
8GB? are you also running other apps at the same time, like a browser with multiple tabs? WoW is getting awful RAM-hungry. 
Loading screens are one thing: addons slow them down a LOT. SSDs sped them up a LOT.
Apart from that, when you are clearly in the world or in an instance, is a separate issue.