IMPORTANT UPDATE!!
Tried Windows Memory Diagnostic but it stopped halfway through, left for about 18hours and didn't complete so that didn't work.
I dived into the blue screen errors a bit more because computer was now crashing without even playing or starting the game, turns out something was screwing with my paging file. So I went and changed the setting on my paging file size changing from automatic to manual on my C drive and that fixed it, previously is was 16GB now its around 7GB, no more crashes and played about 40 hours of the game, battles, sieges and defences with no issues. I am starting to slowly increase the graphics settings and have been able to have a battle with 1000 troops so this issue can be closed now. Hopefully the game gets optimized and I can set all my graphics to high in the future but for now all good, time to go conquer the map!!!
-Thanks to all on this thread who posted help and suggestions.