I find that Pilot2ATC has some unusual restrictions with regard to adding a visual approach for IFR flight plans. Normally it seems that if you try to file an IFR flight plan without an instrument approach, you an error dialog suggesting you add the recommended approach, or manually add one. It won't file the flight plan. Visual approach is not provided as an option for manually adding an approach.

Recently I was filing an IFR plan to an airport that didn't have any instrument approaches so it automatically added a visual approach.and generated waypoints for the visual approach to the active runway (nice feature).

a) Why is it required that I pre-select an approach to file a flight plan?

b) I feel like I should be able to select and assign a visual approach for any IFR flight plan.

While bending the rules for SIM purposes, Pilot2ATC attempts to adhere to real world rules.  And because rules might vary from country to country, there may be more bending than desired by some.

In general, in the real world, you must specify and IAP (Instrument Approach Procedure) to the destination airport on an IFR Flight Plan.  So that is the general rule for P2A.

Also, in the real world, you can file IFR to an airport without an IAP as long as the weather there is expected to be above certain minimums that would allow a visual approach and you include an alternate airport.  At present, P2A does not allow for alternates, so that part is waived....but at some point might find its way back into the logic.

So P2A requires you to specify an IAP on an IFR flight plan.  If the airport doesn't have one, it will include a visual straight in so that you can fly anywhere on an IFR flight plan.

If you want vectors for a visual approach, even if your plan has an IAP, you can request it from the controller regardless of weather or flight plan type, and you'll get vectors.  Generally you can do this once transferred to Approach or when you begin getting arrival instructions from Center...some airports don't have Approach Control.