Rates on a DSCR are in the high 6s if you have a good credit score and experience.

Good luck!

I use travelers for almost all my STR policies. pretty solid insurance and good price

I'm honestly surprised, right now our only debt payment is a 857 mortgage, no car payment no student loans no credit card debt, and good credit 740's. she doesn't make just a lot (41k a year) but with the 857 mortage payment, her debt to income shouldn't be much over 25%.

Then whenever a good opportunity arises, you can simply write a check out of your credit line and purchase in cash.

Your post is under the house-hacking section, do you plan to house-hack and live in this property that you purchase in Jacksonville.If you are planning to live here in Jacksonville, it is important to choose a good neighborhood that you would enjoy living in.I personally like the 5 points/riverside, San Marco and Southside/Baymeadows area.These areas have more resturants/activities than other parts of Jacksonville in my opinion.

Correct, generally once you receive a good estimate by doing recent sale comparisons in the area of your existing property.

It's no guarantee but it's a good place to start.

I would say Corby makes a really good point with regards to the MI that you pay with FHA. 1) I definitely would refinance into conventional (if that is an option). 

Good luck with your project!