i'm going to guess it's not possible with the same model

you can't make anything from nothing and you can't completely get rid of anything
this applies to morphing an object with 6000 verticies to one with 7000
where did the extra 1000 come from?
not to mention, what happened to that vertex who had two edges and why does this one have five? (ie, why don't all vertices in the first model map onto the vertices on the second model?)

you could, however, have some kind of inbetween point where you'd mucked up the shoe and chair and just switch the two models

however, this will lead to a lot of bad things and it would take forever to set up

just make the chair and shoe with the same vertices and same connections.
if vertex A connects to vertex B in one model it has to do the same for the other
as far as i know, for blend shapes to work, each vertex in one model has to map onto another vertex in the other model and more than one vertex in one model can't map onto the same vertex in the other model