Vedana and sankhara and two different things.
In the five aggregates we have: rupa, vedana, sanna, sankhara,and vinnana.
As you pointed out earlier, vedana and sanna are mano sankhara. So, they are part of sankhara, but they are separated from vaci and kaya sankhara because they (vedana and sanna) arise with each and every citta.
So, vedana is very different from vaci and kaya sankhara.
I think it will become clear if you had read the following post:
Vedana (Feelings)
The website is getting bigger, so it may be hard to figure out where to start.
Anyway, let us keep the discussion going, because these are important issues. I can see you are making a strong effort, so I want to help you figure it all out.