The answer to your first question is: Take the bike to a bike shop and have them remove the headset. Also have them install a new one after the frame has been painted. What "threads" did you crush? On the fork steerer or the headset cup? If it's the fork see if the bike shop can clean them up. If the damage is bad enough you may need a new fork.
The "cable hanger" is available from many sources, probably including the bike shop I recommended above. You can get them mail-order too. Here is one source:
http://www.jensonusa.com/store/produ...le+Hanger.aspx