I think the micromanaging of the foes list would be great! It should satisfy the whiny complainer who wants his foes list to be double-edged (ie, he could be automatically placed on the foes list of anyone he places on his own), without making that the case for those who don't happen to like that option. It amazes me that that guy doesn't realize that he can just put anyone with whom he doesn't want to play on his foes list as well, and that solves the problem of them joining his precious games very simply, but whatever.
Personally, I prefer to have the option to join games with those on my foes list (one-sided foes list), and although I rarely do it, this option should definitely remain. Let's not forget that choosing with whom you are and are not willing to play certain games is also a method for expressing superior intelligence and game strategy. It would be nice to receive a warning, however, when I attempt to join a certain foe's game, just to remind me, as I don't memorize the names of any of the JERKS on my foes list. Their names are irrelevant -- I just put them there and forget them, much like filthy, used toilet paper after it gets flushed!
Also, there are many different reasons why members have placed other members on their foes lists. The majority on mine are there for being all-around JERKS, and I don't ever want to play any game with any of the JERKS on this site, nor do I want to see their envious forum posts or babyish game chats. However, I could see possible cases where I may want to allow certain individuals to join in my games, but may want to disallow verbal communications from them.
Still, I think the best and most practical setting is the one on the foes list as it stands today (you could call it a "one-sided universal" option). This option should definitely remain as one of the choices, perhaps even as the "default" foes list setting.
Overall, this is an excellent idea, and as long as the present setting remains, I think the more detailed and specific the options for micromanagement may get, the better.