He managed the rentals, provided a personal asset as collateral for a Line of Credit, and helped manage the rehabs. 

If you are restricting their collateral, yes they can.

Is the income from those notes subject to Louisiana State Taxes, or the state in which the note was originated, or where the collateral is?

To this end of you have 4 properties at 6% and rates go down to 4% are you allowed and does it make sense to re Fi then all at same time assuming there is the collateral Quote from @Christopher Watson: Yep...higher interest rates absolutely kill what little cash flow you may be able to earn. 

Their concern is they have no collateral if things go south.  

Gamble wisely.And you need to very clearly understand the risk trade-off that they do not bother to explain: you're trading a secured contract with your property as a collateral for a (most likely) UNsecured contract. 

Next, any note buyer will be comping out your sale, as you mentioned, 66K is on the high side of retail, going higher will simply be discounted off the top for the market value of the collateral.

@Jessica CarvajalNo bank is interested in giving mortgages in another country and they won't take collateral in another country so I'm afraid you're trying something impossible indeed.

Most hard money work this way:Rates: 10% to 14% (Most Deals are 12%)Terms: 1 Day - 24 Months (Most Deals are 6 months)Fees: 2-5 points(%) of loan amount paid at closing (Most Deals are 3 points(%))Minimum Loan Amount: $50,000 Max Loan: 65-70% of After Repair Value(ARV) 100% Rehab Financing Available (Most Deals require 20% of purchase price down payment or cross-collateral)Closing Timeframe: 48 Hours - 3 Weeks (Most Deals are 10 business days)NO PRIMARY RESIDENCES, NON-OWNER OCCUPIED ONLY, BUSINESS AND COMMERCIAL USE ONLY.

I have 2 helocs and am getting a commercial loan right now using a property as collateral but I generally buy with cash in the 10-30k range and then borrow about 50k per property.