The way I understand it, the objection to electricity is based on an aversion to corrupting and time-wasting appliances like television (and more recently video games and computers). But if the power plug is on someone else's property, they aren't going to be tempted.
Yes to some extent although some churches allow generators, at least for their shops. As far as transportation goes, you're right. That's why they allow scooters and not bicycles.
Some of their power equipment is pneumatically powered with diesel driven compressors. I also read about a hydraulically powered shop.
Another funny thing is that they allow telephones as long as it is in a booth outside where they can't hear it ring. I even heard about one shop that was allowed the use of a computer -- as long as they kept it in a booth outside.