It is the act of pollination that causes a female plant to then produce seeds. Without the act of pollination there will be no production of seeds so it is not like an un-pollinated female will produce seeds that are not viable, there will just not be any seeds at all.
So in short you do not pollinate seeds, you pollinate the flowers of female plants and that will cause the plant to then produce seeds.
Yes the seeds in the pot you purchased were created when the female plants the pot came from were pollinated.
Yes when female plants are pollinated it does take away from the quality of the pot because an amount of energy that would otherwise have gone to create more and higher levels of THC and bigger better buds was diverted to the creation of seeds.
That is why seedless pot costs more, because it is better, it is higher grade.