[Heel n Toe]

With what you said about what you found structurally, this is the type of house that comes apart really fast in even the weakest tornado. Lawd, they just don't make 'em like they used to, huh?

Ask around and find out who is an honest, well-respected contractor in the area and have him meet you there and give you an assessment of what he would recommend as a minumum for getting things fixed properly, and there is nothing wrong with telling him that the owner would love to do a complete redo, but money is an issue.

Is there enough soffit so that some soffit vents could be installed? If so, get a price on that.

Also, re: ridge vents; you can get ridge vents that have a strip of zinc running the full length of each edge and that will go a long way towards retarding mold growth, if not eliminating it entirely.

I would bet the builder used the absolute bottom-of-the-barrel shingle. Try to at least use a higher quality product on anything that is replaced.