Hello all!!!

I have the LotRO mac client for about a year on my mac but i still have problems enjoying the game.
I own the following mac:
Imac 8.1(2,8 intel core 2 duo)
ram: 2gb
GPU: ati radeon 2600 hd pro (256 mb)
OS: latest OS provided(10.8.4 currently)

When the client first came out I had major issues playing the game. Now after the latest update i can run the game and quest(maybe do a solo instance) in very low settings with a minimum lag and frame drops here and there. Wandering in bree is tough and sometimes the screen blacks out and i only see the minimap until the graphics load properly.
I have tried the ultra high settings in isolated areas(last time at the pick of the colossus in evendim) and i had less lag than i expected(i think that my GPU can handle the game graphics on low settings very good. and maybe i can get it to medium high without any problems)

I am thinking of maxing out my ram(getting it to 6gb). So my question is: Will this be enough for me to enter raids and stuff(currently when i get in a raid i have insta-crash and when i go to events i have serious lag issues and fps drops)?

I dont want to spend money if it only ends in me playing solo smoother. I want to get into the group stuff but i dont know if the ram upgrade will be enough. Plz tell me if you know. I fear that the only alternate i have is to bootcamp the game again(but i really dont want to do it. it would be like buying a mac to play windows..)

Thanks a lot in advance!!!