Dunno, would be nice and more balanced if in PVP, player's HP would be set so the weaker player (one with less score) had more HP and the stronger had less... like, 80 and 120... with regards to the styles of the player's decks, maybe?
Yeah, this seems way LESS balanced. Besides, I have faced plenty of players in PVP with thousands more games played than me but way less (like, 10-20% of my total) score. These people probably have experimented with way more decks (accumulating losses) and are probably much better at deckbuilding than I am, with way more upgraded cards and nymphs at their disposal. They are the people that most consistently beat me in PVP, too. Score has nothing to do with how good a player is.
EDIT: Forgot to respond to OP! I am in favor of more PVP options (specifically, the PVP1 Duel and PVP2 Duel options that have been floated around), but I think there are a lot of other aspects of the game that are more worthy of the developer's focus. Also I think choosing your HP would have to be in Duel only, otherwise you would just end up with all the rush decks playing together, all the slow decks playing together, etc.