radicalnan your approach is all motherhood and apple pie and doesn't even consider the effect any of this man's actions have on those around him. The OP has made it clear the sleepover was so big it caused annoyance to the neighbours and was hard to control. That sort of event ends up with accidents and health and safety issues.
Using this home for running a business is fraught with difficulties. Have you not read any of the posts pointing out that household insurance could be invalidated, whether any claim was the result of the business or not. There could be HSE implications, part of the house could be liable to business tax.
Of course most of us are willing and able to help family members where we can, but there are limits and I, for one would not want to host anything that invalidated my insurance or had potential HSE problems, or would cause problems for my neighbours.
As for saying if the neighbours complain they are a miserable bunch. Have you experienced neighbours having a noisy party without warning the night before you have a difficult and important exam? Or neighbour's visitors blocking your drive when you have a sick person in the house who may need to be taken to hospital at short notice. Or a charity event at a neighbours house where the parking is so bad, six people have to move their cars to allow me to get to an urgent medical appointment.
You must live a charmed life.