Commercial seed sorting is done by dropping seed past an air jet and any light weight ones that blow away are deemed "unworthy" as indicated by their lightness. All "full" and heavy seeds pass through the air jet and fall into collection tubs and are deemed "saleable".
Seeds are usually harvested a certain amount of days from/after pollination or after manual examination and usually a combination of both.
In my own breeding experiments, winnowing on a windy day is good for getting rid of light weight and unviable seeds.
As to determining if seed quality relates to plant quality, it seems there are no connections. As long as a seed germinates and sprouts, the resulting plant that emerges can be just as high quality as one coming from a light coloured seed or dark seed.
It is confidence inspiring to plant the biggest and darkest seeds first, however, there is no guarantee of dark seed = good plant.
I usually use the lighter coloured seeds for germination tests. Doing side by side tests with light coloured seeds against darker ones from the same plant, I have generally achieved identical germination percentages, with 99% being common with fresh seeds.
White and/or greenish seeds are definitely no good, but anything from light brown to black are good.
Using pollen from hermaphroditic females will not be feminised, but regular seeds that when in flower will have genetic dominance to being hermaphrodite plants themselves. Feminised seeds are created with chemical manipulation, or can occur if pollen is collected from stamens/bananas which have appeared on female plants very late in flowering and very sparsely, perhaps 10 or so on the entire plant, that is, one or two stamen per flower and maybe only half a dozen flowers on the entire plant. Any male flowers that appear in bunches and at multiple sites, these are the text book definition of hermaphrodite.
Remember too, when it comes to using your own seeds, don't use all the best ones first, keep some better seeds for future plantings.
Hope this helps,..........
Organoman.