If having more teams in the playoffs is great then they should put 24 teams in the playoffs or maybe all 30. They've already destroyed pennant races. Making the regular season pointless would be the next step.
A salary floor wouldn't discourage tanking at all. You would have bad teams purposely trading for past their prime players with bloated contracts (paid for by the large market teams either with cash or with prospects) so they can meet the salary minimum while losing just as much as they ever did. This happens in the NBA all the time.
The number of wins in a season is a net zero sum. If there are winners there must be losers. "Tanking" is not a real problem, it is an inevitability of math.
The union is against more revenue sharing because it takes money out of their pocket and puts it in the owners' pockets. It doesn't make teams more competitive. If anything it creates a permanent underclass of teams that primarily exist so the large market teams can have someone to play. It discourages teams from trying to generate more revenue locally because they can just run a low payroll and all of their expenses are covered before they even start the season. Every dollar a small market team generates locally is a dollar that gets taken out of their revenue sharing at the end of the year. It's socialism for billionaires, turning ownership of a small market franchise into a no-risk investment vehicle.
None of these proposals by the ownership or the union address the real problems with the game. There is less action happening in more time. The current version of Major League Baseball is the most boring baseball I have ever watched, especially in the postseason. It's the best athletes in the world standing around waiting to see if the batter hits the ball over the fence or strikes out. I wonder why I even start watching a postseason game, knowing I'll be going to bed in the middle of the 6th inning because the games start at 7:30 and end around midnight.