Jeff thanks for your great contributions to this site.
I think you are well aware that this subject has a history with fans (47 years worth) that are integrated with the way they view the role of the manager and complexity (or non-) of pitching/substitutions strategy, and those roots run deep for some. As a fan of an AL team, I like the DH. When discussing the value of the lack of DH in the NL with say a Dodger fan, (I know, gross right?) I can appreciate the passion they bring to the argument. To that mind, they like that the decisions are not as easy for the manager and introduce an unknown potential penalty in exchange for giving yourself an advantage. I understand their passion for it and who's to say that some of us wouldn't feel the same if the Angels were expansioned into the NL in '61? I like that the two leagues have this differing aspect. It speaks to their history that they were once truly independent leagues. But to answer your question, incorporating new league-specific rule changes would have to be looked at carefully, but on a case by case basis, yes I'd be okay with some. Probably not with any rule that affects how balls and strikes are called though because that isn't something a player can easily adjust to going from one series to the next. Some might argue the same thing for AL pitchers having to hit all of a sudden in interleague and that is valid but that argument is just not as compelling to me. Rules like the 3-batter can be implemented in interleague without giving any significant advantage either way.