1. Rather it's strange. Usually men and women have different interests enough and logically for their hobbies and different kind of talks they prefer people of the same sex. When you have friends and as you say many friends of opposite sex then there is question - what is the basis of this "friendship". And very logically that you ex was not excited and upset with your friendship with women. It is obvious that for being in frienndship with someone you spend time on those people, in your case you spend time on other women. The question is why?
What your needs your ex-partner didn't satisfy then? And even if you treated her as a princess or even a quieen,
if you big amount of your time spent not with your partner but in communication(what kind??) with another women, every woman would be upset with this, unless she is not busy with "many friends-men". Because one thing if you have hobby as soccer, fishing etc and spending relaxing time with your men friends or staying alone relaxing with drawing or playing guitar and other thing when you spend your spare time with women? Why?

2. It is possible. When passion goes away and amount of past offences is to huge that partners can't love each other anymore and their ways separate but already they feel are so close as relative, probably they have some common friends and business etc, they can stay in communication. Otherwise if new partner of someone is too jelaous that can be a problem.

I'm not sure I understood clear your bonus question so no answer on that then.