Unfortunately it isn't possible to negotiate extensions before the contract is up, as teams do in real life. Perhaps we'll see it one day, along with the MLE and other salary cap details.
2005 doesn't really have any development graphs/charts, if that's what you mean.
And yes, those cheats/workarounds have been in the game since the days of NBA Live 2000/NBA Live 2001. Cheap strategies, though they are undeniably effective.

I personally avoid using them, though sometimes I'll switch primary and secondary positions to make a deal more appealing. I don't consider that cheating, especially if it's likely the player you're trading away would shift over to their secondary position should the trade happen in real life.