I'm all for free living and thinking outside the box or whatever expression you prefer, each to their own. But when done it should be done properly.
Insured as a commercial yet used for private purposes, unprofessional conversion and log book not marked as a campervan/motorhome. How legit is your insurance policy? Do they even know you've modified it?
What happens if you crash into me looking around for your late night covert parking spot, or your gas installation leaks and blows destroying my property that you parked beside (hopefully you're not in the van, genuinely)?
You'll still be indemnified by his insurance if he hits you/damages your property or even blows up your garden furniture
However, he will possibly be open to being pursued by the insurance co. for the costs to pay you, but that would be between him and them..