I'm not sure how attractive the numbers will be however when looking at HOA dues, insurance, taxes & the unpredictability of future costs with HOA dues.

. $418,000 @ 3.125% on a 30 year fixed is $1,790.61 - what is the remaining $1,171 - taxes and Insurance?

Also, there may be some tax benefits if they can qualify for federal funding based on low income. 

Easy to use yourself too HELOC works (there may be some places that do a HELOCs on rental properties)I personally have used a 401k Loan on a few occasions - You're essentially borrowing money from your 401k and paying yourself back (interest goes back into your 401k as opposed to a bank) and if you don't pay your 401k back the loan would simply become a withdraw (maybe some tax penalties, but you could probably finagle a workaround).

Though I am unsure how I would amortize the up front remodeling costs for P&L, tax accounting.2) Interest only loans term loans -  Would allow current owner to have cash flow on the property, without eroding the asset value. 

A lot of forum members are experts in their respective fields related to real estate investing, whether that is real estate sales, wholesaling, flipping, buy and hold investing, lending, self-directed IRA and Solo 401k investing, or tax and legal guidance.There are some pretty nice discounts on many products and services offered as Perks to BP members that you might want to check out: https://www.biggerpockets.com/perks/proIf you haven’t been to it already, the Bigger Pockets blog features links to their fantastic podcast and many great articles: https://www.biggerpockets.com/renewsblog/The site has quite a few tools that can be helpful for new members.

Yes, do the tax exchange if you can.  

In North Jersey, buying is difficult from my beginner perspective with high prices, property tax, etc.Barrier to entry feels high in my area.

Since you're looking to expand into Florida and other states, I'd recommend starting by narrowing down your focus:Market Research – Florida has great opportunities, but each state and city has different laws, taxes, and demand drivers.

On your tax return you would report the proceeds, subtract costs and proceeds paid to seller, then the remaining profit would be your flat fee.