In no particular order.
Playable D League and Summer League Games.
I believe (correct me if I am wrong, I'm not a 2K player) 2K had a feature where you could play D League games, along with sending and calling up players as needed over the course of your dynasty season. I would love to see this in the Elite series.
As for Summer League games, sometime during the off-season, most likely before the "trade period", you could assemble a roster of 8-12 players (rookies, free agents etc), and play the summer league games against other NBA teams. This would allow you to see how each player plays, their strengths, their weaknesses etc.
Rookie Combine
Much like the summer league, you could run players through various drills and see how they stack up
Better computer generated rookies
I know in Live 05/06, the rookies weren't too bad. But in the later versions of 09/10, I constantly see either A. the same rookie over and over, or B. a completely unrealistic player. For example, a black players with blond hair and a red beard. Cheeses me to no limit.
Bring back individual practices
The "team play" in the academy is nice, but I would like to see EA bring back individual practice and one on one games. No reason for these, just some good dynasty pictures
.Multiple team trades and sign and trade deals
3 (or more) team trades have been lacking from EA basketball franchises. As for sign-and-trade deals, although this is a little far fetched, if EA could work this in, great.
More complex resigning process
I've noticed that free agent players always want to return. I would like to see some free agents refuse to resign or demand trades during the season. EA could also incorporate "No Trade Clauses" like 2K has.
28 & 56 game seasons
82 is fricking long.
Improve players by playing them
This would give players an incentive to use their bench and rookies.
Bring back the assistant coach
In NBA Live 06, you could higher an assistant coach to help train and improve your players, bring this back.
The ability to higher/firer your Head Coach
Same as 2K.
Change teams in Dynasty Mode
However, you shouldn't get to pick this. Teams that finished poorly the season before should be options.
Be a pro mode
Something similar to the 2K version.
Dynasty mode is that deep in Elite 11, it's a sure buy for me.