4. When you're flying for real, there is no room for serious mistakes and a flight sim can never project real fear or panic, which is essential for learning and developing your reactions
No VR can't replace IRL- but. Once you've had some time with IRL flying (i have 160 flights now) you will transport your IRL flying feelings to VR. When I do cross country glider VR, my palms can still get sweaty and my heart rate can go up when I get too low and can't find a good thermal.