As an Airstream newbie myself (who also bought from the same dealer ... probably), welcome. Outside of a few things, I don't think most of the learning you need is unique to AS. I think it's the whole RV thing.
I do find it surprising that rock guards aren't on the 22. We have a 23 and it has them, but then it's dual vs. single axle. Honestly, I never even thought about that when we were looking. But after reading various threads here and watching some of the videos on youtube, seems rock guards will save you some $$$ in the long run.
Have fun in your AS. We've only made one trip in ours (a short visit to Marble Falls), just to take it out and find any issues (we found a strange one). I'd recommend if you haven't already, doing something similar. Nothing worse than finding out something isn't working quite right when you need it (turns out the first time we needed our heater in our previous camper, we found it didn't work ... 30 degrees without heat isn't exactly fun).