A couple of points since your car is new to you (lessons from personal experience)...
Do not ignore air leak issues. They cascade and are very expensive to repair and will eventually cause the compressor to burn up if you ignore leaks - that's a $500-600 part depending on where you get it.
- You should consider the airmatic bags/strugs like shock absorbers on a regular car. The air bladder will eventually leak. Just like the struts/shock will eventually need replacement. Cost doesn't make it a design flaw, it's a wearable component.
- It is wise to replace the front struts and/or rear air springs in pairs. The MB OEM parts are crap because of the material the bladder is made from. You can find replacements from Arnott Industries. Many here (including me) have purchased them. The rears are very easy to replace and require simple tools and a little patience. The fronts require some mechanical skill. There is a good thread if you have the skills/tools. There are threads that talk about indy replacements for fairly low cost.
- Replace the airmatic relay!!!!! It's $20 from MB. It's a green relay in the main panel (3rd replay from the left as you look at it). I think the far left one is the starter relay. If the relay fails closed, as it did in my case, you will be replacing the compressor. I took apart the old relay and the contacts were toast.
- If you hear a loud WHOOSHH when you turn the car off, it's the exhaust hose from the compressor. It normally connects to a muffler in the fender well.. In my case it cracked at the compressor. Simple to fix and you can get the hose from any parts place. I cut off the cracked end and reattached it. I'm sure MB gets some rediculous price for it.
- You talked about the height being different. As the other poster mentioned, it can be calibration. However, IF one side/corner is high, you need to consider the valve distributuion block. It opens and closes each port independently to adjust the height. If you have the vehicle significanly high on one or more corners, you may have internal leaking in the block. It's quite common. The dealer replaced ours under warrantly. I think the part is a either $200 or $400. It looks fairly easy to replace but i don't know.
If you take the car to the dealer you can expect the following screw job.... they will tell you it's the valve block first, then the compressor and then the airbags. They get about $700 for the valve block another 1000-1200 for the compressor, 1800+ for each of the front struts and 1000+ for each of the rears. You can spend a lot of money at the dealer in a hurry. If you get the parts from somewhere like Arnott, and get an indy to do the work or do it yourself you can save a significant amount of money. There are good threads in here for how to do the work if you have the tools and skills.
last piece of advice.... if the car falls at a corner, its almost always the air bladder. You can read of lots of threads about how they couldn't find the leak, etc. The air leak is caused by road dirt and just the wear of rubber against metal. When your testing for the leak you have to keep in mind you have a 5K pound vehicle weighing down on the bladder and it almost always seals the leak until it's a big leak. If you want to attempt to find the leak, pull the 40A fuses for the airmatic in the fuse block and lift the vehicle where you extend the suspension. Then do soap bubbles (you'll have to take the wheel off). I've read where people have done that and it didn't show a leak. Don't forget to put the fuses back in.