The Gear Sport 3g models have a little battery with a ribbon connector, like a mobile phone. HB00334 Model number EB-BR730ABE 300 mah 3.8 v I dont know what the non 3g models use.
that is a head scratcher. Can you tell us, can you be heard if you use a headset ? either or both , wired or bluetooth? if the problem remains on all microphones, it is likely in the software settings , if it works through headset but not the handset something is up with the hardware.
the piece that is actually bent , is down inside the molded boot of the cable. there are replacement three ring 3.5mm jacks that you could, replace that one with, if you can solder. OR, i am sure any local computer / phone repair shop would be able to put a new jack on that for you.