My goal is $2,400/mo in passive income, and no debt or debt that pays for itself.

Personally, I do more notes than ownership of properties at this stage in the cycle but again that is partially preference.Also, if you are accredited you can do more passive investments of larger debt or equity deals. 

For example, I think we are late cycle, so I lean toward the safest part of capital stack which is debt (or debt free equity).

A HELOC may have a minimum monthly payment requirement (often "interest only"); however, the debtor may make a repayment of any amount so long as it is greater than the minimum payment (but less than the total outstanding).

They want: 600+ credit scoreNo eviction/felony/criminalgood rental history and steady jobbut if there is an application with low credit score, they ask for more deposit. or any debt or these kinds of problems.

BMO Harris Bank, 65 the Illinois bankruptcy court held that the Chapter 13 debtor, the nephew of the deceased title holder of the property who was the mortgagor under a mortgage with a due-on-sale clause and received title to the property pursuant to an Independent Executor’s Deed, was not in violation of the due-on-sale clause because, as the court stated: Under the Garn–St Germain Act and its implementing regulations, a mortgage lender, among other restrictions, “shall not exercise its option pursuant to a due-on-sale clause upon ...

Eliminating recurring consumer debt to a manageable level if not completely, and budgeting.For example, clearing that $800 in CC debt or personal loan is better than seeking a property with cash flow of 300 dollars.Starting from a lean budget with a 3-6 month emergency fund is more plausible.

Here's a quote from the article Steve linked to: "If you are already struggling with debt or barely getting by, then a money merge account isn’t for you.

There is also a provision of Right of Redemption, which if I understood that correctly, states that the previous owner can come back for the property as long as they make good with their debtors?

If you dislike debt or any kind, except for your primary residence - a la Dave Ramsey - you're going to want to pay those properties off as soon as possible.