yes but talking of truespace he still can't weld vertices of diff objects as far as i know (and there are some limitations even if they are both of the same obj)
you will have to a little different thing:
move one of the two objects far from its position, where they don't touch each other
unify the two objects using booleans (so no edges are created by booleans)
connect the vertices that need to be connected (so the edges of the faces that are going to be joined) with the new edge tool
move the object to its original position
weld the vertices that need to be welded
(note: ususally you can't weld two vertices of two different objects that you have unified with booleans but that are not connected until the two vertices are not connected with a new edge)
after little experience with this strategy you should be able to avoid in most cases the use of booleans to connect two different objects, but at the same time it is a way that may sometimes give some problems when you create manually edges/faces
about you second question, what edge editing are you talking about btw? the only editing that *may* have probs are i think (as said before) welding vertices and creating new faces while creating/drawing new edges, and they happen usually if you do something wrong
