While viewing, I noticed that the buildings weren't there, either from inside, or outside the aircraft. After hitting ESC to stop the replay, everything appeared again.
Known issue of all our sceneries, due to their nature of not being entirely contained in BGL files. It can't be fixed in any way, because the instant replay doesn't replay objects created in C++ with the Simconnect api.
You can use the free FS Recorder, which doesn't have this problem.
I noticed that when using "Park Me" with a 737, the height of the indicator sign was too high to view once I got close enough to park. Would adjusting the seat height make a difference?
Yes, changing the eye position will help. The ideal solution would be using a TrackIr, which makes it way more easy and fun to use.