Interiors do usually require a few screw holes but not that many. You need to decide on the interior that suits your purpose and go from there. Are you a wkd camper or a Euro tourer? Do you need to cook, eat and sleep in your bus for a couple of weeks or just drive it to shows and club nights.
Loving the beetle , I regret selling ours. Tbh I preferred the beetle over the camper to drive. This is a very helpful and friendly forum
I'm sure I'll miss it at times, but I've been very impressed with how the Bay drives (ie not as bad as I thought it'd be! Feels very tight, which reflects work done by previous owner).