This is interesting. Glad nothing else was burnt down!
A damp cloth should do the job to clean all the black soot inside the oven. If that doesnt work, just use some chemicals that is mentioned in the manual (a non abasive one).
The drum shouldnt be too much of a problem. A bit of detergent and a scrourer should do the job.
Im sure the Behmor is fine. Just make sure nothings melted or looks out of place. Test all the buttons as stated in the manual and start a dry burn (ie 1/4 --> start).
I think the only reason why it caught alight is because you introduced oxygen by opening the door. This gives any glowing embers what it needs to flame up.
Next time, keep in mind you have the cool button incase it gets too far past second crack.