I like strategy and variety, both of which are more important parts of baseball than any other sport. The DH decreases strategy, and so I want it gone. But I'd rather see it only in one league than in both. That adds variety and keeps more strategy at least in one league.
Since I like variety, I enjoy that the ballparks are different and that the dimensions may favor one type of hitter over another. That adds strategy to the game (for example, saving your lefty starting pitcher for a game in another park more favorable to LHP). Having different ballparks also adds to the strategy of team building.
I also think the pennant races should be made fair, so that teams competing for the same playoff spots play the same schedule. It would be a shame if the Nationals beat out the Phillies by a game for a playoff spot because they had more games against the Orioles while the Phillies were playing the Red Sox. I think interleague play makes fairness impossible; so I'd get rid of it. I'd like to get rid of the wild cards as well, but with 30 teams, that would be impossible. If they expand to 32 teams, they can do away with it and have teams compete for playoff spots only within their divisions. Their interdivision scheduled can be the same.
I think a pitch clock would help. Teams have learned to deal with the limit on mound visits, and players can adapt to a pitch clock.
I wouldn't rule out a split season format, but I would need a specific proposal to react to, complete with how trade deadlines and roster expansions would work.