I would definately replace the dogbones...bent dogbones, or for that matter any binding or wobble in the drivetrain can be very hard on motors...

If you're interested here is an excellant write-up on lipo's, so you don't toast any morehttp://www.rchelicopterfun.com/rc-lipo-batteries.htmlCredit to finding this site goes to Duster_360...

Good Luck, Racer53