6216m2 motor found... what to do?
Generally speaking, the 4.5V motors have higher torque than the higher voltage variants, but run at a much lower RPM.  I have never personally tested this particular motor so I can't say specifically.

Utility is in the eyes of the beholder.  For some people, this would be the exact motor they need.  For some, it would be useless.  It's hard to say if it would be useful/less without a specific application.

You can always order the LEGO branded cable/connectors from Bricklink or similar sites.  However, it's quite easy to make your own cabling for the 4.5V motors if you are so inclined.