I can do whatever the hell I want all on my own if I feel qualified. As to homeowners insurance, I don't think there is anything in there that specifically states that I can't personally do the work. I'll double check for sure now that I know what I am looking for. It doesn't really matter though since building permits aren't legally required, and everything is being done according to code.
Building permits aren't legally required??? Whoa, note to self - do not move to WV! Definitely don't want to move into a house wired/built/plumbed by Goober without any checks by appropriately knowledgeable people.
Around here you can generally do most any work yourself, provided you pull the appropriate permits (professionals must also), then get the work inspected by the city inspector (which is part of the permit process).
We don't have a city inspector. We have a county planning commission. They regulate new construction and zoning. Professionals are subject to their own professional codes. Now don't go thinking that all of WV is like my county. I happen to live in a subdivision (which was fully regulated and subject to subdivision building permits, codes, and regulations when it was built), in an unincorporated area. Just a mile away is a fully incorporated town that subjects everyone to building permits and the like. I grew up in a town, which was also subject to building permits.
Take a scenic drive thru some backroads in WV some time. You will be astounded at some of the "buildings" that pass as houses. Did you know that hubcaps can be considered window shutters, and two sheets of plastic is a "WV double paned window?

That is why when you buy a house, you ALWAYS get a thorough home inspection done, and possibly also structural inspections, pest/insect inspections, etc. If a problem is found, you can follow up with a more specialized inspection. You do this stuff with any house you might buy, whether it is in an area like Chad's or in an area like mine.
There really is nothing to worry about if you take the necessary precatutions.