No danger whatsoever of stinging as never aggressive.

These pollinates fruit trees and other beneficial plants.

Behavior described here:
Batra, S. W. T. 1980. Ecology, behavior, pheromones, parasites, and management of the sympatric
vernal bees Colletes inaequalis, C. thoracicus and C. validus. J. Kansas Entomol. Soc. 53:
509–538.

I'll leave the ID to somebody else, but I would say that ground bees as a group are very important in pollinating, especially if the (non-native) honeybees continue to have problems with colony collapse disorder, etc. The danger of stinging is approximately zero--unlike honeybees, paper wasps, and yellowjackets, ground-dwelling bees are solitary (though many may nest close together) and can't afford to sacrifice themselves for their nests.