It's just a mini fan assisted oven. We cook everything in it, jacket potatoes, steaks, bacon, burgers, fish, chips etc. Best kitchen gadget we've ever bought.
Quick rinse after each use (while it's still hot). We've had ours two years and used almost daily.
Yes you can cook lots of different foods, chicken, sausages etc.
Can you cook frozen chips in these or just fresh cut ?
I don't think it hard to keep clean. I've been using mine for more than 2 years every week and the food bowl is really easy to clean.