So I decided to fire up Medieval 2 again and take it for a spin

I loaded in as the byzantine Empire
I've played the game quite a lot, but it's been a while, but I've never seen the AI this agressive

In just 30 turns, I got DoW's from:
Hungary
Sicily
Venice
Poland
And the two most confusing:
Milan
Papal States (!!!!!)
I killed the Pope in open battle O-o

Anyho, is there anyway I can prevent this from happening?
Very hard, very hard btw

P.S.
Any recommended vanilla enhancement mods?

EDIT:
Oh also, I distinctly remember alliances calling you into defensive wars, right?
With this popup asking you to choose between the agressor or defender if you have both allied
this doesn't seem to be happening though, so what use are alliances? (same for protectorates)