A less then full investigation may result in one thinking that the house and or the house and tennis court lots were what was being sold.As I later found out, a newbie tax lien investor thought they were getting a great bargain by outbidding other misinformed investors and paying the back taxes, legal fees, and an additional $34,000 (overage) which the county forwarded to me.  

While I doubt I'll be investing here (terrified that property taxes and the pension debt will ultimately cripple property values), I'm always interested in meeting new people.

The owner does not want to extend the debt for 30 years.

Also, you will likely only be able to use the rent to offset the mortgage pmt debt on the rental property to $0 since you dont have any Sched E history yet. 

Trying to decide if we should use a home equity loan for the remodel, do we need to put current home under LLC to help with debt to income ratio & would that affect getting the home equity loan?

Does not affect your debt to income for future loans in the mortgage industry (auto loans could look different, but i would think similar so hopefully no worries there). 

. - I will ding their credit such that all credit cards and other debt will cost them more.- I will keep their security deposit for funds owed.- I will do my best to garnish future wages until their debt to me is paid in full.This has worked 100% time so far.  

Quote from @Monty Alston: Quote from @Travis Timmons: You need more income, not more debt.

Owning a duplex at 20 is a huge accomplishment, and it’s inspiring to see you’re already planning your next move.From my perspective, real estate investing is a long-term game focused on building equity, paying down debt, and maintaining stability over chasing short-term cash flow.

Long term $ can range from 6's-10% range depending on all types of factors - LTV, location, unit count, debt coverage, borrower strength, full doc or lite doc programs, etc..