Doesn't happen often, but you impressed the hell out of me. I love the way you think!!
Now, onto hubby. What he's doing is completely wrong and some would call it cheating. While he may have had "permission" for certain things, he's not upholding his end of the deal. This lifestyle can not work if you don't have trust.
Unprotected sex??? That's just silly WITHOUT having someone else at home to think about. That's a major mistake and one that he needs to know is not acceptable anymore. You're doing a great job of processing, but rules are rules and that's one that affects your life. Not something to be playing with.
Not calling at night...BIG NO NO!! I agree 100% with the idea of keeping things as "normal" as possible when he's not home. If that's the routine why is he allowing someone else to disrupt it?
I think you've done a great job of thinking about things and trying to realize where your feelings and emotions are coming from, but how he's acting is not fair to you. He's doing what he wants with no concern for your feelings. That's not polyamory at all.
I look forward to hearing more and I wish you the best of luck.
Live life to the fullest 'cause you never know if you're gonna wake up tomorrow!