G33k

The flight controls pretty much snap to their maximum authority, this leads to excessive stress on the aircraft and oscillations with SAS enabled. The control surfaces need to move more gradually, ideally this would also be tweakable by the player. In the FAR mod for KSP you can enable a feature that adjusts the maximum deflection based on the vehicles speed, like a real aircraft FCS would. Also would be a good improvement.

In KSP 1 you can pin the periapsis and apoapsis of the resulting orbit of a maneuver node. You can not do this in KSP 2 and so you can't do it accurately. While you can hover over the nodes and get the altitude while the node is not in edit mode, you can not do this in edit mode.

The maneuver node can not currently be used to plan orbital insertion burns, it burns on the node (which is set to the Apoapsis), this leads to failed burns as they start too late. With no indication of the burn time on the HUD the player can't even decide this for themselves. Considering the burn time is probably the most important metric in manually executing a burn it's basically impossible to do this accurately.