But I liked the lower downpayment (15%) and lower interest rate (6.75% vs 8%+).

You qualify as a Real Estate Professional (REP).Keep in mind that the big play is accelerated depreciation to lower your tax burden which in turn increases your cash flow for that year.

I should’ve mentioned that we currently have a 6.875% rate and just looking to refi into a lower rate because we want to take someone off of the mortgage, came across someone who offers a lower rate and curious if anyone else can match that rate.

With properties rented out and mortgages covered at minimum, I will be able to save 8k/month.First property I have a year long lease in place and that cash flows about $200/month (expenses $1450, income $1675).

Granted, that is for people that have perfect credit, putting down a large down payment, lower DTI, etc.

Additionally, house hacking is usually the cheapest way to get into real estate investing due to accessibility to conventional mortgages with lower down payments and interest charges. 

Only considering because we could sell both tax-free being primaries 2 of last 5 years, and expenses are going up on both, and we may be able to get better returns elsewhere.

4) What are the monthly expenses?

As you may well know you need the down payment, net worth equal to loan amount and cash for monthly expenses for generally 9-12 months. 

Florida is easier for flips and most areas are much lower price points.