those I think the basic of my questions.Thank you for responding and helping to understand more. 

It will familiarize you with the basic terminology and benefits.

Quote from @Erick Pena: A "good" rental property is one that covers all expenses (mortgage, taxes, insurance, maintenance, property management fees, and any other costs) and still leave a surplus (commonly referred to as cash flow).Calculate cash flow as: Cash Flow = Rental Income − Operating Expenses − DebtThere's much more to it, but that's the basic idea.

It will familiarize you with the basic terminology and benefits.

So basically in my mind this would not be a great financial move as we be accruing about 200k more in debt if we were to sell one house and take the cash from there and use it as a down payment.

At it's basic level:Assumption: Asking the bank to turn the loan over to you and going through the normal underwriting process, credit, income, DTI ratio etc SubTo: Taking over the loan without telling the bank, no underwriting, no credit check, no income verificationBoth have risks, but it's not my intent to be detailed in this post.

It will familiarize you with the basic terminology and benefits.

Since 2021-2022 and the surge in prices in basically all markets across the country, how are fix and flippers evaluating properties.

Since 2021-2022 and the surge in prices in basically all markets across the country, how are fix and flippers evaluating properties.

We typically pay somewhere in the range of $3500 for a new, basic furnance, including install, if there are no other modifications to the system required.