Well it turned out that the cpu was indeed the culprit to all my woes and has now been replaced and is currently undergoing testing at ocuk with the graphics card, ram, backplate, new cabling, new psu and triple block fitted. I'll be getting it back on Saturday and I can't wait, it's been horrid using this macbook as it's useless for gaming.
Tbh I've never had a faulty CPU either, GPUs, yes - motherboard, yes - hard drive? yes haha
Put all that bad times behind you and enjoy your gaming.