Ideas are psychological (not physical) existents consisting of concepts or combinations of concepts—ideas have no physical qualities. Ideas can be reproduced indefinitely without requiring any physical substances of components (resources). Ideas can be used indefinitely without limiting their availability or existence to other users. Ideas cannot be "used up or destroyed."

I am not so sure about using a manufacturing concept (reproduce), which implies physicality, in conjunction with the reproduction of an idea, which, you state: “…have no physical qualities.”  If ideas have no physical qualities (I have no idea as to which sort of physical qualities ideas have, by the way) then just what is being reproduced?  Is reproduction of a non-physical entity possible?  

Clearly there is a context problem involved here: A) we have mental events, which, I do take as existing as, of course, mental events, and B) the bringing into existence, in the non-mental event context, the idea which represent the mental event.

This entire going from the mental to the non-mental, in my opinion, is too…awkward of a method of showing why an existing product ought to be legally replicated by a person whom does not hold the patent, or did not invent it.  

Although I do not agree with your “Ideas are not physical,” I do, however, agree that I should have the right to make my own “Cadillac.”  I mean, it is MY effort that is going into bringing THIS “Cadillac” into existence, not the men and women at the GM plant.

On the other hand, I would not feel comfortable calling it a Cadillac, and selling it as such, despite the fact it can be identical in every way, as I would be deceiving the purchaser of his perceived quality assurance that he/she is accustomed, or expects, from GM built Cadillacs. 

If it is clear as to who made the product, I see no problem in the replication and the distribution of the replicated, either.

Analogy time:

If I build a house that looks just like a house built by a housing development company, the only thing I can’t do is sell it as a house built by that housing development company. 

A person, who digs into the side of a mountain/hill in order to create for him/herself shelter, used his/her intellect/abilities to do so.  Should I be forbidden from making a similar shelter because I didn’t come up with the idea first?  I know that this analogy is technologically inferior to, say, MP3s or a modern house, but it holds.

 
If one is not willing to build a cave due to not being the inventor, then you must be willing to stand out in the cold.  I, for one, am not willing to do so.   

 I find myself in the uncomfortable position of agreeing with the principle of copyright laws but disagreeing strongly with some of the actions undertaken to enforce it.

quote I would say that this violates the property rights of the purchaser by preventing him from listening to the CD he has paid for on the device of his choice.