Everyone would still contribute, as you correctly stated, but at a MUCH higher level, like a team sport SHOULD be played. Face it, pitching is entirely too integral to winning games in baseball, and particularly in WSB. There is no way to sugar-coat it.

Move the rubber back again. Give 4 strikes. Limit pitcher's innings or games per week. I don't care. I'd just want to see pitchers be a part of the game, not the majority of the game. I'd also like to see them bat. It adds to the strategy of the game and also makes for fewer beanings/brush-backs.