...the conundrum I am facing is that the Timberwright wants to start the design process and I am still trying to figure out the "trust" part of what was described earlier...
If this is the actual conundrum you feel you are facing, I would openly share that with the current Timberwright and explain your position...
If the current Timberwright wishes to "design something" without a contract or the rest of the plan and understanding between you both, that will be a learning experience for him...
...I am trying to nail down all the aforementioned factors (species, finish of timbers, spans, and bent design) while leaving the joinery decisions for the most part, to the Timber Framer...
If you are taking on the liability and responsibility for the frames structural capacity, then leaving the "joinery decisions" up to an experience Timberwright is an option. I think I have a good handle on this craft of timber framing, and I still would guide my client and their project towards having a PE sign off on the design. Sharing the burden of "liability" and "good engineering" with a licensed, and insured PE that has timber frame knowledge is well worth the $500 to $2500 it costs on average...
If cutting a frame for oneself, then perhaps this may not be a necessity, yet I know I won't do this without the "peer review" of having my work examined by others...including a PE whenever possible.
I have tried to design the frame such that the floor plan is simple and flows from the bents. Are there other details that I could resolve that could help me at least get a quote?
If your current Timberwright is not willing to give you a solid "estimate" (low to high) at this stage, then I would continue to looking for a Timberwright that can...This is an indication of competency.
I may not have suggested this yet, but I now I tell all my potential clients that I want them to be 100% confident in my relationship with them...That starts by me strongly encouraging them to get at least three quotes from equally skilled Timberwrights.
As for an estimate, you do need a "solid design" that will not change.
This has to come from you, or and experience designer. It the "Designer" is also the Timberwright, they should be able to give you a price for these services and either include them in the final price, or give you a price outright for their design services...
