I wouldn't worry about making supplemental payments to pay down the loan earlier.

Some times hobby landlords think they can keep tenants longer by supplementing there tenants rent and will charge $50 -$100 below market.

I am finding a declining response rate with each supplemental letter I send.

Louis,The big value add players refi (if they are using a variable rate loan) or obtain a supplemental loan (if they have a nice fixed rate in play) to pull out cash as soon as the property renovations are completed.  

I am looking for mostly a passive income stream to supplement my other income sources.

I'm trying to balance building wealth for the future with having a supplemental income.

Once I list my rental, my lender will write me a check for the 20% that I had put "in" my deal and I use those monies to move onto my next deal or to supplement my bank account.

Are you trying to find a place that will cash flow you nicely each month or a place that supplements your payments and is nice to live. 

I want the money I make from paid for rentals or even a few rentals that arnt paid for to supplement my pension.

When I was 20 I bought my first investment home and then used the money generated by that investment to buy more investments and to supplement a shot-term lifestyle I will never regret.