Swap

Yes. Target one (minion or artifact) and target another (minion or artifact).

The two cards are simultaneously teleported to each other's location. If one of the targets cannot be targeted or teleported (e.g. Iron Man Talus), neither target moves.

No. You target both cards being swapped, and targets must be in the same region as the caster. See Casting Spells for more information.

If either card was being carried by a unit, that unit will be carrying the newly swapped artifact/minion, due to the golden rule. For example, if two carried artifacts are swapped, the bearers will be carrying their newly swapped artifacts (even if they both are in the same location). If a minion is swapped with an artifact, presumably the minion will be immediately dropped (unless the new bearer can carry minions) and the artifact will not be carried (unless the swapped minion was being carried before it was swapped).

Choose one of the locations the oversized unit occupies as the destination of the other card. See 'Teleporting Oversized Units' for more details.