"...discover the problems on the drafting table..."
My thinking exactly. BTW i seriously suggest you invest in a low cost 3D cad system. On my current project we (collectively) moved from 2D to 3D (Ideas NX). You will find it bottoms out your concepts much better, since your 2D drawings are not linked to each other. When you come to drawing, the 3D model is the template, so it is much easier to assemble.
Maybe SolidWorks would be well suited to you. Whatever stage you feel the project is at, believe me it will benefit greatly from a move to 3D. For a start it is much quicker and easier than your blue styrofoam mockups...
"... rotor-to-rotor vibration ... yaw control."
Agreed about 3 blade rotors, but 4 blade rotor Unicopter is definately complexity overkill. You would be much better getting into retreating blade feathering (or ABC) by this stage - the ultimate way to avoid downwash interference vibration.
BTW i'm confused on rotor rotation direction of Synchrolite --> Unicopter. If Unicopter is a development of Synchrolite (which is by far the best engineering approach) then i really would settle on one rotation direction - ideally outboard advancing so inboard can (eventually) be feathered. Don't get hung up on roll/yaw coupling, since you will otherwise need to develope 2 stabilty scenarios - bad idea (unecessary development), besides vert stabilisers and aumentation will help. You may even be able to hand over componentry and tooling...
"Yaw control should only be a concern when considering autorotation...."
Hmm, longitudinal differential cyclic: bad idea on helicopter where rotor clearance reduction is an objective - seriously risking an extreme manouvre clash accident. Electric motor idea interesting, but complexity again. Considering differential collective ineffectiveness/reversal in autorotation, i really don't understand why the controls would be reversed as long as rotor loading was >0g - the concern comes when in a reduced g situation, such as pushover.
Are you really against cable operated tip (or even hub) spoilers? The linkage could be arranged so that spoiler only comes in when rudder and differential collectice ineffective (ie large pedal movements required), at the risk of unecessary complexity. Maybe it's my turn to eat crow...
"...look into the interleaving."
No, i'm convinced intermeshing is the best solution (thanks for helping me see this). Too much risk of interleaver shaft failure, and besides you go back to all the retreating blade problems. Ideal rotorcraft is feathered retreating blade synchropter - let Vertol play with SBS tandems...
Mart
PS: check out
www.midwestcontrol.co.uk for control linkages.