If a character has 2 (or more) targets and TK, can they place two characters with the one TK action?

TELEKINESIS POWER: Minimum range 6. Place one target friendly single-base character or object within range and line of fire into another square within range and line of fire. That square must be within 6 squares and line of fire from the target’s current square. Characters placed with this power can’t use Telekinesis this turn.

The answer is in the power. It is one target character so that won’t work unfortunately.

Can a character with two targets mind control two different pieces in one roll?

Yes they can. Mind Controlis an attack so if you have 2 bolts or more you may target that many opposing characters.