I'm really impressed by this mod, but one thing I noticed is that you almost need to create your rockets in free-play mode, because you get at most 2 launch attempts per mission with the budgets here. It's awfully difficult to design a rocket to meet the criteria from scratch without opportunities for some trial and error. One interesting thing to consider would be creating two commodities, cash and public will. Then you could have an open-ended "R&D" mission allowing users to create rockets freeform at a cost of dollars per public will (to simulate politicians resisting the spending). Completing missions would cost money but could generate public will, especially for big projects like a moon landing. It would require rebalancing, but it would make the development trial & error part of things integrate into the mission control instead of needing to occur outside it.