Now we can focus on pollen as a topic. When you dry your pollen in the dehydrator, what is the time frame involved? I would expect that it would dry reasonably quickly.
It does. I didn't do any pollen collecting this year (too many mean bees in the apiary over the spring and early summer), but if I remember from the previous year I think it was about half a day in the dehydrator.
Is the nutritional value of the pollen reduced or changed in any way during the drying process?
I would doubt it alters it much. Honestly, there is not a lot of literature out there about the digestibility of pollen to humans. It would probably be most nutritionally accessible to us if we were eating the bee bread out of the cells, because the bees have fermented that pollen. But until someone invents an easy way to harvest bee bread out of comb, it's not really feasible.
If you're going to sell pollen for human consumption one of the issues is cleaning it. You can make a cleaner with a piece of air duct and a fan. Or you can buy a top entrance trap and keep you colony with a top entrance all the time (otherwise they don't work well). With a top trap the pollen is already very clean.
I have a bottom mount trap, and you do get little bits of hive debris in the pollen sometimes. Since I'm not selling the pollen, I just hand pick out the obvious bits. It's important to empty a pollen trap very frequently, preferably daily, to keep the moist pollen laying in the trap from molding or drawing other insects to it, and that frequent harvesting helps to keep the debris down as well.