[Toaster]

Hello again Paul,
Sure its possible, anything is possible.
It sounds as though you wish to make a "mock" up apperati to iron out details. This is where a "sketch" of sorts out of "popsicle" sticks worked for me.
I approach the feasabiliy aspect with a "larger" model to make things more then "paper good". What looks great on paper takes on a whole different life in the real world.
I assemble/partially assemble the project with common materials to examine movement(s) and possible control elements. If this proves useful, I try do downsize to the scale that the project is intended for. At this point, I have mechanical drawings to back up a "mock" build.
Now comes the problem/expense. With the mechanical drawings and your "mock" (you may or may not do the mock part but it helps bigtyme!) to a fabricator that can/will work at the scale you require with materials you stipulate.
If you catch the fabricator during off times, they will be reasonable in cost. In thier "on" times, they will be prohibative.

When I built "Herbert" (my annoying mechanical apperati), I went in steps. First was motivation, next was control elements and finally came "intelligence" (poor word as its not really applicable)
After now 7 years in the making, "Herbert" can only recently navigate "steps". (slowly I might add) In the past 2 years were the "leaps" of voice navigation and verbal annotation of "his" movements. (babble, babble, babble!)
He can open a door with a standard door knob or handle but the process takes about 3 min. for the "logic".
As for your human hand project, please continue but remember that it takes time and should not be rushed.
While I probably took a differing route that yours, I had many of the pitfalls that you WILL incur.
Your device may need more "active elements" (bones and such) then that of a human hand due to complexity of the muscular assist. A trial "big scale" build will enlighten and maybe shed light on other ways to achieve the same results.
I dont know how much help I could be using E-Mail on such a project but feel free to write.


Let me know if i`m failing to get the jest of your questions or project.