They are also willing to sign it over to me at no cost other than what's already accrued/ repairs.

I am in Landlord Cooperation Program but still unsure if a lien will go against my property since the amount might of accrued before entering in their program.

May not use it much but can accrue great signup points for business travel. 

Your nephew makes interest payments to you monthly or accrued.

I just came across a lien note with the following language “Prepayments will be applied to installments on the last maturing principal, and interest on that prepaid principal will immediately cease to accrue.”I had a few people look at this and got 2 different interpretations so casting a wider net for consensus and feedback.

Account Closed Here, they would be code violations, with fines already accruing, utilities, etc.  

@Amy Spransy you do not need to worry about the Junior Liens, I have purchased around 40 properties at sheriff sales over the years and I have never had an issue with Juniors, you are responsible for back taxes if any, and this years accruing taxes, Municipal charges like special assessments, back water bills, Noxious Weed Cuttings, or city snow removals. but other than that you should be good to go, Oh you are also responsible for Occupancy, like if the borrower or a tenant is living there, and there is some debate regarding value of personal property left behind, but thats up to you to decide. 

If the Association is well run, major expenses are generously accrued for, and there are no onerous rental restrictions, I wouldn’t be concerned about that aspect.

Ensure that the amount due is either a.) credited to you on the the closing statement, or b.) paid by the title company from the seller's proceeds at closing.Whether service has been shut off for non-payment or by request, as long as the water company has record of a meter present at the property, charges continue to accrue.

Based on your feedback for the specified states, the interest is on principal only which makes sense.In an example I’m thinking off, if I were to purchase the certificate from another investor, any legal fees I accrue as part of obtaining that investment, to my knowledge, get wrapped into the total debt due at redemption with only the principal lien amount earning interest.