I will just address this part, as most everything else you are bringing to the table hinges on it.As for inferences, I'm sure we can agree that fems are less stable than m/f seed, and, should they be used in breeding projects, threaten to pass a greater degree of instability on to successive generations.
No, I do not agree in any shape or fashion. Just what do you have that would point to there being any evidence of feminized seeds being less stable that those of a M/F breeding?
Any sort of anecdotal report of a single grow is not going to cut it, no matter how many logical conclusions you make.
Many make these same claims, none have backed them up.
A true selfing is only detrimental due to the fact that it is a bottleneck of genetic material available during meiosis. Nothing about the procedure produces less stable genetics.
I would also be curious of what vendors you think are providing feminized seeds that were brought about from less than desirable breeding practices. You mentioned about "what you are seeing"...well, just what are you seeing? Do you have some sort of insight into these vendors breeding programs and how they do things? Really, just what are you seeing?
Surely you aren't seeing massive reports of hermie grows and bad fem seeds are you? I sure don't see that in any fem seed thread. What I do see is folks listing a multitude of fem seed offerings that they have grown and had great success with. I also see the never fail arrival of the person who throws all the charges at fem seeds, yet never backs up their rants.
It often ends up bad because some just can't come to the reality that they are doing nothing but passing on bad juju for no good reason, and claims that are simply unfounded.