I think we all can understand your concerns. The first question to ask your self is how is his home looking. Look real close at the small details. Is everything tight and secure? Is the job professional or is it sloppy work? A general contracton doesn't have to be on the site all the time. Do hire quality subs though.A good sub just needs direction and a set of prints,they will do the rest.Also,your father-in-law will learn from the mistakes he made on his house. I,myself, would spend the extra money and have a hired contractor to oversee everything. There is to many small important details that the inexpereinced person can miss. This is only my opinion. How to convince the rest of the family is another problem . Good luck, Ron J.