Does embedding rebars along the face provide tensile strength to a load-bearing wall?
I had to read your question a few times, but I still don't know how you intend on reinforcing the walls with rebar.

You cannot simply put rebar against the existing walls and cover them with some mortar.

For rebar to be effective, it must be embedded in the proper thickness and rating of concrete for the load.  the concrete supports the weight and the rebar helps keep the concrete from failing or displacing.  I really think you may need a little on site professional help here. Unless you know how to pour walls, footers etc, you may get in over your head.