Here are my fixes:
Either both leagues have the DH, or neither does. Personally, I don’t think they’re necessary, but I am a realist, and “We’re getting rid of DHs” will be followed immediately by “Today’s game is cancelled because of player action (i.e. an MLBPA strike).”
Electronic strike zone. It shouldn’t be that hard to implement. Of course, you’re still going to have the human element involved with check swings, unless they go to the NCAA rule, which, IIRC, is, “If the bat goes past the far front corner of the plate, it’s a strike.”
Add two more teams, and have four four-team divisions in each league. Each team’s schedule would be 22 games against each division opponent, 12 against each other team in the same league, and 3 against the teams in one division in the other league. The main reason I support interleague play is because this is where most real rivalries exist (e.g. Yankess-Mets, Cubs-White Sox, Dodgers-Angels, Giants-A’s, Orioles-Nationals), but if scheduling the rivalries every year is considered too unfair, then go back to no interleague play.
You want to make the All-Star Game really mean something? Any player voted into the game’s starting lineup that does not play, for whatever reason, is treated as being on a 15-day disabled list. (A player already on a DL would not be penalized unless it was less than 15 days at the break, in which case it is extended to 15.) Let’s see who doesn’t take it seriously now. There’s a reason nobody plays the day before or after the game.
If interleague play exists, then give home field advantage in the World Series to the league that won the most interleague games that year (not counting rivalry games that are scheduled every year). A tie goes to the league that didn’t have it in the previous season.
However, the real fix is, make the game affordable - starting with the parking lot. Not every stadium is served by reasonable public transportation; this was a serious problem when the Giants were still playing at “whatever Candlestick Park is called this week,” as the subway and light rail systems didn’t go within a mile of it. (“The version I heard was,” when they designed BART, the 49ers still played at Kezar, and Candlestick was (and still is) in one of the poorer areas of the city, so it didn’t make sense to build tracks to somewhere where pretty much nobody would go between October and April.)