I just got the Core Set and two expansions in the mail yesterday and i'm about to dig in and try some single player games. I'll see what how it goes and continue to post my thoughts and ideas on this forum. Feel free to add comments or your own experiences.

I've done the same as you, got the core game and enjoyed it so have just bought the first two Mirkwood expansions. However, I play 2- player with my son. After several games I think we're playing it correctly now