Similar to how the console versions of Diablo work, where you press Circle or what not, and it picks up everything around you. Is this possible, with any macros or mappings, to do in Diablo 3 for PC?
No, there isn't a way to do this.
Certain items (gold, potions, blood shards) will be picked up automatically when you get within a certain range.
Everything else must be clicked one at a time to pick up.