Others have stated my views already. But there is something else I am wondering, as well. What about platonic friendships? Are interactions with friends similarly restricted: no heavy communication, meeting no more than 3 times a month, no sleepovers, etc.?
If that is the case, I'm inclined to think this isn't really a healthy relationship, because the persons involved aren't allowed to have significant, genuine relationships with other people. That rings abuse alarms in my head.
If that is not the case, I guess it isn't unhealthy (at least not to the two people in the primary couple), just a bit.. illogical? How is it that you can have a deep, meaningful relationship with somebody as long as you're not being sexual/romantic (not sure how they define partner vs. friend), but it becomes a threat that you have to restrict as soon as you are? The person suddenly becomes a threat at that point? I don't think the sex/romance would be worth the rulebook to me, I'd just skip that part so that I could be free in the rest of my interactions with the person.