Originally Posted by Chammock
When does that happen? LOL
Welcome! Results on that vary, especially due to variations in dealers. Avoid the trap of the dealer saying, "Just leave it and we'll call you when it is done!" Some have waited for long weeks without their new coach under that scenario.
You might reduce the noise by adding a layer of FatMat under the doghouse. You'll find extensive discussion on all the things you mentioned with a search. Further reduction would come from using the same stuff under the dash. It will never be as quiet as a car or pickup, you are sitting right on top of a big V-10 engine, designed to rev high on steep hills!