Better manouver planner:
Planning a manouver should not only show the required delta V but also the available delta V of all stages and the current stage.
We should be able to lock a target and have the game calculate a vague interception manouver. This should also come with time and date so we could complete several orbits to get the best interception timing.
Mission planner:
Basically the manouver planner but from the complete start. We basically select a launch pad and then plan our mission and all the required burns. Like for the manouver planner we will be able to select time and date for the best timing (for example on mars missions)
This will then give us a delta V requirement for all burns and delta V per burn (mission plans can be transfered between rockets)
And then we can build our rocket with these requirements instead of just building a rocket and praying to god it has enough delta V