Personally, I am for MPPV as a win condition, but I'm not 100% sure I favor it as an innate game mechanic as opposed to say a card effect (ie. Level 4 MPs with "When you reach 5 anger, you win by MPPV"). I'm not sure if this change would cause complications, or make certain MPs significantly more powerful, but I think it could extend to a new way to balance these MPs. Of course, contrary to what many would say, I'd also push for MPPV to be given mostly to low power level MPs like Krillin or Hercule, as opposed to higher level MPs like Goku, Vegeta, or Trunks despite it making minimal thematic sense (at most, it would be the weaker personality bluffing, or the stronger personality just deciding the fight wasn't worth it and leaving [giving an effective win]). This is to balance the lack of access to decent AT stage damage, instead largely relying on flat stage/life damage and high pluses. It would also give less competitive MP stacks more recourse to be played (to cite others examples, Villain!Vegeta could be an interesting contender for MPPV, as could Turles).
As for making the game more interactive, I actually have found the game in its current format (admittedly FanZ since i missed the PanZ window by literally two months) than any of the other games I play (which, ftr, include Pokemon, Vanguard, Duel Masters, Final Fantasy TCG, Yu-Gi-Oh, etc.). Perhaps this is mostly my limited experience playing locally in Aus, since I've never seen a highly competitive scene and am coming in at the conclusion of the game where many of you are talking about the game state at the release of different packs, but the sheer amount of interaction between me and my opponent, not to mention the fact that I cannot effectively test anything beyond opening hand when practicing alone, gives me a sense of a much more dependent relationship between me and the opposing player than I find in Y-G-O (where, absent of Hand Traps, first turn plays go through without hindrance and normally decide the match in top tiers). Perhaps there is a way to make this more engaging, and I agree that a more concise set of rulings for the interaction of card effects would be helpful, but I don't feel this game is low on interactivity in its current state.