She says she does and it has no debt.. ( I paid 130k for her house).

That said, green card is not a legal requirement for closing so buyer could waive this - though I don't see why they would unless deal is great for them.

I am currently enjoying my 1k monthly income with no debt, and I am nervous about leveraging.  

Quote from @Charles Fay: Hello all, first time posting and wanted to ask for your advice.currently in the military awaiting a 9-12 deployment within the next 6 months.I will have ~150k savings after deployment, 85k before, with no debt, payments or anything other than basic bills, 750+ credit.

DOS or more commonly known as Event of default.Alienation of title is an event of default in most all debt instruments not usually located in the Note its in the mortgage  deed of trust etc.And along with other Events of Default  IE non payment of Insurance or tax's or waste these all give the lender the right to Accelerate the note but not the obligation..

and, something that doesn't get discussed enough - a record number of properties don't have any debts on them. 

INstead of just saying "no" we asked them to check with their credit card company if they offer travel insurance yada yada.. we got a 5 star review form them without giving a refund.

In general, multifamily properties are a popular choice for investors because they offer the potential for cash flow, scalability, and the ability to amortize debt across multiple units.

So well within the 30 day trial period.However, they continue to bill my credit card for the service in spite of the confirmed cancellation.Has anyone else had any issues like this with them?

You can have multiple conventional mortgages and have a great credit score as long as you don't pay late or get too close to the maximum debt to income ratio.