I think there is difference though between loaning something and renting it out. The premise of each one is different in Islamic principles though. Loans are not given for profit whereas renting is basically a profitable transaction. Loans are meant to help someone else whereas renting is meant for your own individual or self. Loans are not a source of earning though renting is.
Though what you have stated is interesting if we look at it from the perspective that money can be rented for our use. There is one factor which you did not touch upon, when something is rented you do not have to return the value of the rental principal itself but rather just pay the rent as long as you want to use it. To me this might look like an interest only loan in which nothing goes towards the principal balance (which is what you have rented for your use). So then if I took an interest onyl loan for a period of 20 years, then after paying the rent or interest on it for 20 years without anything towards the principal amount I took I should not be liable to pay anything of the principal back after the expiration of 20 years. What you are saying is that I go an buy a principal balance for a certain inflated amount and agree to pay it back over a period of time. This is not renting.
