1. A bit more attention to detail with the presentation - just simple things like showing the scorecard after 'simulating to player' would go a long way to the basic enjoyment and immersion to the in-game scenario.
2. Classic matches/scenarios or challenges to give a bit of variety.
3. More customization to career mode player to gain sponsors/ bat signings etc.
4. Not sure how difficult it would be to implement, but starting your career at one grade lower than what it is now. ie: Club cricket before state/county cricket.
Probably not too difficult given the team customizations already available? This would give an added tick for realism, rather than averaging less than ten as a no. 3 for a state team and constantly being picked.