Ill take a shot at some of this. If the plant has a perfect flower, that means the bloom has both male and female parts, you probably dont need pollinators. Think tomatoes, peppers, and beans. The wind will pretty much pollinate them. An advantage of bees is they that shake the bloom, shake the pollen lose, and cause pollination. Usually the first beans I get are in one spot that looks like a bee was active pollinating them, but probably what actually happened a bee was just buzzing around down there, not necessarily moving pollen from flower to flower but shaking the flowers. Once I start picking the beans I dont have pollination problems. I think I shake them up enough just by picking to not have to rely on wind or insects. So pollinators don't hurt, just not totally necessary.
Things that have separate male and female flowers like squash need pollinators. Wind alone cant do it.
Many fruit trees are the only example if something that just can't self-pollinate but need a totally differetn variety to pollinate them. I can't think of any vegetables like that, but maybe someone else can.
Then you have corn. Doesnt need pollinators at all as long as the plants are close enough together. Those send off so much pollen from the tassels when you get a breeze that some have to hit the silks and pollinate them. I have been known to walk through a row of corn if I get poor germination and a poor stand and just use my fingers to collect a little pollen from the tassels and shake it in the silks. Im convinced this helps if the stand is not real thick.