1 - There were multiple glitches in the first month or so that really led to this. The completion missions, the 3x innings people got for playing conquest, etc.
2 - You just aren't stopping this. And really, I'm not sure why you would. People are playing the game, people are spending money. Beyond that, you aren't stopping this anytime soon. Tie up those two loose ends and people will figure out another way to farm xp points. Besides, I don't really think that's killing the game anyway.
3 - The tax is already high enough. You tax it any higher and the market is going to die. Besides, the tax isn't so people don't develop super teams, the tax is there so stubs get taken out of the marketplace.
I understand the frustration of people having stacked teams by spending tons of money, but I think SDS did a decent job to combat that this year. How? By the grinding missions. As I had time off from work and was in the middle of a huge move, I had a ton of time to play the game this year.
My lineup currently has these FB Diamonds: Fielder, Kinsler, Larkin, Beltre, Berra, Gywnn, Ichiro, Bautista, Holliday, Murray, Papelabon, Zobrist, Brett, Carew, Wagner, Dawson, Banks. . . I have 3 total diamond LIVE players (Arenado, Rizzo, and Betances) How much money did I spend? 50 bucks when I didn't realize that packs sucked so hard.
In addiction to inside edge, that would allow me to complete with anyone if I didn't suck so hard at the game. (I don't play a ton of online, the computer on all star is challenging and fun, I don't feel the need to play online)
With all of that said, I agree 100% about how the search engine should work. I don't think the minor league tier system is correct. It should match up teams with their ratings. It would make things a lot more enjoyable and add a layer of strategy for people.