So my search for possibly actually owning a game has now evolved into the possibility of just buying a license to an existing game. However, I really don't know what this means. Is it time limited? How much ownership do you really have? What are the advantages/disadvantages? Is all of this negotiable? How many of you have sold licenses for your games and was it a good experience?

I am unsure what exactly you mean by 'licensing'. Your questions sound kind of like you are talking about publishing. If this is the case then I think that everything is negotiable.

Licensing just means that the owner of the game grants you a license to publish the game under whatever terms you negotiate. This could be exclusive, non-exclusive, limited to certain formats/territories (or not), limited to a certain timespan (or not) etc etc.

In short it is all open to negotiation.