"Bonus in Snow"??

I just bought M2TW and Kingdoms. I think they're a big improvement in many ways. After playing a couple of short campaigns (as England), my biggest complaint is the AI sending other faction's troops to hang out on my turf without Military Access having been granted and the fact that ALL northern faction troops seem to get a snow bonus. This results (in my observation) in the AI attacking only when it's a snow day...when it attacks at all!

2 questions- 1\ How come I get in trouble with His Holiness/ other factions when I attack marauding freeloaders?? IMO, there should be a diplomatic option of "Pack your bags and get out or we'll attack", or words to that effect and 2\ Is there a way to remove/adjust the snow bonus?? I'd like to try. It might make the AI more aggresive if they can attack year round without a bonus or penalty. The bonus might be forcing it to attack only on snow turns, which might be effecting overall aggresiveness (or lack thereof).

I saw another thread about this (sand bonus for Muslim and snow bonus for Catholic factions), but it didn't address possible AI behavior that they might cause.

I'm playing the Retrofit Mod btw.

Thanks!