An awning is the kind of thing that you might not use very often, but when you do, it is invaluable. Make sure it goes over the door and is long enough. My 21qb is a short class C, but the awning is the full length of the coach part of the vehicle and it is great in the rain or the sun. A power awning would be even nicer.
One thing to consider if you are shopping for a used class C: if it does not have an awning, it might have been a rental.
Absolutely not. When it's 80 degrees (farenheit) and there is no shade, or it starts raining, you can sit inside. An awning just provides another option.
On our cross country trip last June, on more than one occasion or pure luck ? When we parked in the campsites, the awning somewhat kept the afternoon sun from beating down on the side of the MH. Maybe not alot ? but it helped keep the MH cooler inside. And it was nice too when it rained to be able to walk up under the awning and shake the water off the umbrella/jackets, then head on inside..
Not needed Neither are electric heating elements in fridge, water heater Neither are slideouts Neither are leveling jacks Neither are microwaves Neither are........well you get the drift
Nothing, even the RV itself, is really needed. The awning, like the generator, is used according to the individual camper's habits and needs. We rarely use our awning, but some of our friends never park without using theirs.