One department can say no and the next room over, someone might say yes.To your next question, yes most loans do allow you to prepay the principal (rather than “capital repayment”), but you must direct the lender to apply it to principal and not to interest, which can be done online or on the check in the comment section.  

Payments to principal reduces our basis and increases the potential for Capital Gaines in the future.

I would apply the same principal to selecting tenants and avoid churches.

Any gain will come from principal pay down of mortgage.

The license law actually says that you become a principal when you sign the purchase agreement.

Depending on how it is structured, the child may never be able to receive the house if principal cannot be distributed. 

I'm looking to purchase another investment priperty, and am exploring the option of using a HELOC to make a 'cash offer'Is it better if the plans are to just keep all money invested for now, to just pay all extra on the HELOC thus reducing the 'principal'?

Which once able to take out equity from the second purchase and the repayment of the first home equity lone of credit, after having the necessary 20% equity in a mortgage if not needing the money for a current purchase, utilize home equity lines of credit on each mortgage, and use the money from the HELOC and pay down the same mortgage to be paying down the principal substantially faster on each property free and clear. 

Property values have now improved (although still down 10-15% from peak of '07), and principal has been steadily reduced.

On a side note it sounds like you put yourself in a good spot financially and are following some good fundamental savings rate principals.