Take my opinions with a grain of salt since I had no significant experience with VR prior to Quest 2.
Resolution:
If you’re looking for perfect clarity in resolution with the Quest 2 you may be disappointed. A monitor will still look clearer. I’m sure that it would be an improvement over the CV1, though.
FPS:
There are so many variables here that it’s hard to answer directly. Your setup should be able to give a pretty smooth experience, but you will have to do some tweaking of the graphics settings. We all do.
Comfort:
The Quest 2 is not the most comfortable headset around (I would give the Reverb G2 that prize), but it is better than its predecessor. There are many mods and alternate straps, face cushions, etc,., that have been designed to make it more comfortable. Even at best, however, most people get tired in the headset after an hour or so, and need a short break.
Loss of Immersion:
I’ve never experienced the loss you describe. I feel totally immersed in flight from the beginning to the end. However, it might be that I do mostly shorter, VFR, flights in GA aircraft. People who use VR for long-haul airliner flights usually use VR for only the beginning and ending of the flight. I can’t imagine being in VR for four hours in an A320.
Good luck in your decision. Once you try VR you will become addicted.