Fatalah: Can I post here and you post it there? You're already a member.
1) Remove power swing button - Bane of my existence in all baseball game. No hitter EVER varies their strength of swing. Hitting for power is more a matter of the player's natural strength, where he makes contact with the ball, and where in his swing the player makes contact. This garbage led to a shit-ton of homers.
2) Fix the scale for players and the field - Everyone should have noticed this, but it is clear that the players were much larger than they should be in comparison to the field. This created problems with hitting because fielders would be able to chase down just about any ball hit. Completely unrealistic. This would also alleviate the problems with balls staying in the in-field that really shouldn't. I was unaware that every infielder in the MLB was a gold glover, but they certainly cover ground like they are.
3) Remove turbo button for base-running (Or at least the necessity) - It IS a good idea, but if I smack a ball to shallow right field, I should NOT be able to be thrown out by a right fielder who charges the ball and throws to first. Not unless my last name is Molina, at least.
4) Fix 'wind' affect in game - Stupid issue, but the wind made almost every single 'power hit' a home run. Absolutely ridiculous.
That's all I can think of right now. As has been said in this topic though, starting from scratch wouldn't be a bad idea at all. MLB 2K5 is easily in my top 5 worst sports games ever.