Part of your problem is the way you have built these surfaces. They will not join together, because there are edges that are not shared.

If you are going to make a patchwork type object, you have to make sure that each edge is joined to it's neighbours. Use the join command after you create each piece. There is a script to show open edges which you also need to use, otherwise you will overlook some edges that have not joined properly. When you get an eror you have to deal with it there and then. Going back later is not always possible.