I read through everyone's posts and I guess I am the odd man out. I like the DH rule, but it has been around my whole life and wish it would be brought to the NL, mostly because as a fan of an NL team I feel like every time we play an AL team we are at a distinct disadvantage. The AL has someone set to be a DH, who is used to getting up cold and going to bat every few innings. The NL teams usually has some bench player that they put in the DH spot who isn't used to that situation. Also the NL has to have someone that can play the field, having a person just around that can only hit isn't in the best interest of the team. If you look at the interleague play the AL has won more interleague games in 17 of 22 years and there is only one rule difference. Either expand it or delete it so where everyone plays under the same rules. At this point I can't see getting rid of it, so the only option is to expand, in my opinion.
Someone mentioned something about where does it end, should we have a DH for weak hitting SS and CFs and such and I actually will say I heard someone years ago make this proposal and it sounded good to me and would let pitchers, such as Ohtani or Ruth hit and would give the manager some strategy. You get one DH per game but you can use him in the place of anyone, so if you want to DH for the SS when Ohtani is pitching then you can.
As for the speed of games, games don't seem too long to me, I enjoy them. The only things I would shorten are commercial breaks and when a pitcher throws over to first base several times in a row.
Expanded rosters don't matter to me. Put 50 players on the bench. What does it matter? There are always several people that don't make it into the game anyways, unless it is an 18 inning game.
Don't mess with the fundamentals of the game, the mound height, shifts, strike zones, and making pitchers pitch to a certain amount of players. Mound height, shifts and strike zones aren't the problems, it is the notion in player's heads and analytics that says trying to hit the ball 400 ft. every time is better than getting on base and moving players over. The forcing of pitchers to pitch to a certain amount of hitters makes no sense. I understand people hate seeing a lefty come in for one guy, then a righty come on, it takes up lots of time and is sometimes annoying but can you imagine the first time a pitcher comes in and immediately walks the first two batters and the manager is told he can't replace that pitcher. It is going to cause too many problems.
Replay is annoying but at this point I don't know how to fix it. We as fans see every angle of a play and expect someone in real time to make a call that we watch over and over again to see the nuance. If an umpire misses a call we as fans get furious so there has to be a way to check them to protect the ump and the fan but as of yet I have not seen a perfect/fast way to do this so we have an imperfect system.
As a baseball fan, it is very sad to me that we are having to have discussions based on trying to keep fans, while other sports are growing without seeming to try. I don't know the solution but I know baseball needs updates to appeal to a younger crowd. When I was a kid baseball was king and now if you watch ESPN you can go hours without hearing a single baseball topic and during the middle of their offseasons basketball and football are still the number one topics on many programs.