That's a pretty subjective question. The easiest way I can think of to answer it is to say that it's no louder or quieter than other microwave ovens I've owned. In convection mode it's a lot quieter since there's no buzzy magnetron operating in that mode. (There is a convection fan, however, but it's not objectionable.) Easy to clean? Well, the inside is porcelain-lined, and it wipes up pretty easily. I never use anything other than a damp sponge or towel with a drop or two of Dawn on it, following up with a damp towel ... then leaving the door open and allowing the oven to air-dry. The area around the grill element at the "roof" of the oven cavity is a little more cumbersome to clean around, but if you keep things covered when cooking, cleanups are minimal and infrequent. And of course, the glass turntable and the plastic doohickey that makes it rotate lift right out, and the turntable is dishwasher-safe.

The magnetron in a microwave (the thing that makes the microwaves) often makes a buzzing sound that can be mistaken for a vibration or loose part in the oven. It's not. Mine's made that buzzing sound since day one. To confirm it's the magnetron, run the oven for a few seconds in convection-only mode. Notice no buzzing noise? It's the magnetron. Nothing's wrong with your oven.

Yep.

During convection mode, yes, you can -- in 25-degree increments IIRC. Up to 400 degrees F.