[meaubry]

When you refer to wire, do you mean electrical wiring? or guide wire?

There are a number of ways to protect the electrical wire from chafing or being cut when running through sheet metal. One way is to protect the wire itself by wrapping something around it, another way is to eliminate the sharp edge on the sheet metal.

As for grommets. I'll refer to the rule book.
Definition of a fastener: any item that is used for the sole intended purpose to join two or more items together with no other auxiliary purpose or function including Pop Rivets.

Depends on what you are trying to do. If you are joining 2 pieces and simultaneously protecting the wire running through it - you are okay. If not - then fabricate the device from thin sheet plastic (lexan), Rubber, or Aluminim which are all on the additional hardware list.