Ok. so I have 4MO and VB Air. So talking from experience here. A few things, and important that you don't mix these up.
1. Off-roading - as California4x4 says, if you have 4MO and higher profile tyres, you should be good. Just remember, a Cali as an off-roader is very different from a Land Rover in its capabilities. For Norway, you will be fine with the Cali and high profile tyres. For a bit more serious off-roading such as in Iceland, look at posts from users such as bvddob on minimal modifications required.
2. Air suspension height adjustments - again, remember this is not a Land Rover-like capable vehicle. The only time you will need to use increased height is when you are on a tough track with boulders and you would like to navigate over/around them slowly. I used this when navigating some off-road tracks in Portugal last month. Without the height adjustment, I would not have been able to navigate those tracks. The second time I have used it in the last 8 months. Good to know that it is there when you need it.
3. Garage height - remember, the VB Air suspension keeps your vehicle at VW recommended height all the time and therefore not additional wear and tear to the drivetrain or any related components. So in that it is like the standard suspension, but with the ability to lower and park in your garage. That will definitely be a plus for you and work well for you.
4. General driving - Air suspension is not about smooth 'air' riding as many people tend to associate it with ... or the 'pimp-my-ride' lowering. For me, it is to do with the handling. The ride is much better, body roll much less and it feels more like a car. It is well behaved, and that for me makes a big difference.
5. Adaptive Cruise and Lowered ride on motorways - no issues. Again, makes it a pleasure to drive with great handling on motorways and long distances. The lowered motorway ride is not the same as the lowest possible setting. In the lowest and highest, the max speed is about 10 mph. In the motorway lower setting, I think it just comes down my a few mm, but makes for a more planted ride.
6. Bonus - single button levelling - park up at a campsite ... or anywhere for that matter and with the press of a button the van is level. Makes for a much better experience when even having just a cuppa tea. Think about having a cuppa tea on your dining table if it is not on plain ground, or sleeping on a slanted bed - will not be a good experience
Rosmia installed the VB air on mine and they have done a very good job. Their sales support is also good.
IMHO, it is a great and worthy upgrade, if it ticks the boxes for you. I personally would not have a van without VB air now. It is not about being loaded and going for VB Air. it is about enjoying your driving and for me VB Air gives the driving characteristics in a van that I enjoy.