Hi Doug,
For the frame rate limit in the settings, it's up to your experience in fact.
If your computer can maintain these 26 FPS all the time, and that value is comfortable for your eyes, then I think you do not need to alter it.
You can reconsider this only if you face a situation (scenery or plane) which brings the FPS below that value. In that case, you might want to give a try to unlimited FPS... but this may cause some ground blurries, if you fly too fast
Concerning the rest of the settings, should be ok, although I don't remember the FSX constraints so well anymore. If the sim looks fine for you (and it looks quite fine for now in these shots), then don't modify anything.
Concerning NVidia Inspector, you do not need to "set" a profile.
Each sim/game has its own profile. It is up to the NVidia driver to select that profile depending on what is running.
NVidia Inspector simply allows you to edit a profile (or create a new one for a game that didn't have one), but you don't "select" it, so to say. It gets selected automatically by the driver when a game is launched.