Not necessarily. Yes ride height is directly affected by the air in the bag, but volume of air in the bag is also a factor. Smaller or larger bag will require different pressures to maintain the same ride height, all else being equal. Also, most systems have a threaded perch for the bag that...
Sorry but this is false. The air inside the bag is your spring, which has the ability to be adjusted for rate just like a regular spring. Another advantage is being able to adjust the rate on the fly without removing components in order to change the rate.
Performance oriented air systems do...
What size are the gauges? If they are a standard 52 or 60mm why not just fit whatever you want. Some white faced Defi gauges would look really good. Also Stack makes dual readout gauges so you could potentially have four gauges in space of two.