Can I "autoloot" all items?

Nope, gold and orbs must be run over (within a certain range) to be picked up and, like past Diablo games, items must be clicked on within a certain range to be picked up. You can increase the automatic gold pickup range with magic items that have the range property.

If you're out of range of an item, your character will move to a spot close to the item you clicked and pick it up.

Gold and orbs are picked up automatically when you walk near them,the pickup radius can be increased with certain items that provide that bonus.

Other items need to be clicked on.

You have to pick up most items manually.

Gold and Health Orbs, however, are picked up automatically, just by passing near enough.