Agreed.

Scratch building requires so many skills it's almost too much to ask here. This may sound a bit harsh, and trust me that Idon't mean to be harsh, but if you have to ask the question then you're not ready to scratch build planes. As Minnflyer says, start by building kits as you will learn the skills needed from the kit. Most good kits will have instruction manuals well laid out and they will show you how to do many steps. Once you move up to building from plans then you have those skills and you know what to do, when to do it, or when not to do it.

And as a quick answer to your question.Ribs do not need the strength of light ply. Ribs are not a structural component of the wing that gives the wing it's strength. Ribs are to set the shape of the airfoil.The strength of a wing comes from the spar structures in a wing.

Ken