Shortly, my ideas are:
- Add one/two betting shop(s) to rob in LV, I think it makes sense since the city is "the gambling capital of the world"
- In SF, there are only two other places outside the city to rob whenever the city is too crowded with cops (cops are overpowered in SF tbh), Angel Pine and Bayside. My suggestion here is either add more stores/betting shops/etc to rob or expand the area of available places for SF. Both LS and LV have more space to rob/escape anything.
- Add a casino in SF? This goes back to my second point.
- Warehouse robberies? Like having some NPCs and a safe there as well. This can be further discussed.
- Not too sure about this but being able to rob the drug dealer NPC and having a chance of dying "by a knife" would be interesting. Huge chance of failure but it'd be nice.
- Add a bank in Angel Pine? Second point again...
These points are what I had always in my mind while playing the game.
Even if the robbers would have more places to rob, the cops would not be in that much of a disadvantage since they would have more work to do.