This sim is real fun to play. From a current Medium Flight Model player, and realizing, as stated before, that the simplest things require the most effort, these items are just a suggestion if at all possible without the huge investment of time:

Center point (could be gun cross) for Virtual view from front of cockpit. Just so I know where nose if pointed.
HUD option to show just the instrument dials with and without the side text information
Level flight autopilot.

Thank you for possibly entertaining these suggestions.