As long as they're for personal use and not offered for download publicly, that's fine.
If you plan on offering them to others to use, please let us know and we can figure something out as far as attribution is concerned.
You can bind a key to to multiple things by using a semicolon.
For example, in your console, type bind p "voicemenu3;slot1" and P will now open voice menu 3 and use the slot 1 command (taunt).
That's not necessarily true. Bug fixes and minor updates are good when they're consistent. It helps keep the game on people's minds, which helps maintain player counts.
Have you noticed a pattern? Is this something that happens more frequently with certain weapons, or if the player is at a certain health before you kill them?