Has there ever been an INTERIM BELT.....

Where the actual champion is not injured, fully healthy, and able to fight? 

As far as I can recall all interim belts have been created due to an injury with the champion unable to defend their belt. Is Conor the only case where the champion is perfectly healthy but simply chooses not to defend their belt so they created an interim title?

Nogueira's interim heavyweight title. Randy was the actual champ, and he was in a contract dispute.

Then when he came back, he defended the title against Lesnar, instead of the interim champ Noguiera.

Conor definitely needs to step up and defend that belt. Stop with the money excuse. You made enough money in that boxing fiasco. Time to step up and stop acting all weird at Bellator events.

I was pretty disappointed at how he acted that night. Was really embarrassing.

Yes plenty.

Holloway's and Aldo's interim belts comes to mind just in the last year.

Conor McGregor was champion and Jose Aldo was interim champ. Conor was perfectly capable of defending. He was stripped and Aldo was promoted to champion. But then an interim title bout was called for between Holloway and Pettis. This was for no justifiable reason. It was merely created in order to replace the interim champ that Aldo was vacating. One of the more egregious examples of making up a title for no reason other than to have another championship fight and belt holder. There are numerous other examples.

and so on