The wishlist is located here:
https://forums.flightsimulator.com/c/self-service/wishlist/163
The guidelines are one wish per topic. Many of what you brought up have a current wish by searching the #self-service:wishlist and then cast a vote on those you are interested in.
As far as altitude changes, there are some existing bug topics:
https://forums.flightsimulator.com/search?context=category&context_id=200&q=Atc%20altitude%20change%20&skip_context=false