I believe safety should win out.
I agree. Rule 1 "Safety" and Rule 14 "Avoiding Contact" are there for that purpose.
It is not physically possible to keep a good lookout on a spin boat in all cases as there is a blind spot.
I disagree. No matter what shape or how opaque your sails are, you are still required to keep a good lookout. Just as when driving a car, if you have a blind spot, you need to look around it frequently enough to keep track of traffic. If you can't watch where you're going, you should sail (or drive) something else.
A boat going to weather has much better visibility; hence it should carry most of the burden.
I disagree. This rationale degenerates into worst lookout gets right-of-way. I don't think that's the right spirit to sail under. If you sail a boat with a bigger blind spot, you should accept the greater effort to look around it.
Spinnaker has the right of way should be the rule, imo.
Can you suggest a wording for that rule? I have trouble seeing how it would work.
Further, in the interest of safety, spin and non-spin boats should be on different courses whenever possible.
I don't understand. How is an encounter between a spin boat going downwind meeting a non-spin boat going upwind any different than a spin boat going downwind meeting a spin boat going upwind?
Regards,
Eric