Both are important.If you see a negative net migration over the last 10 years, it's probably a pass.If you see a positive net 10-year migration, but a decelerating rate of year-over-year in recent years, that's a sign that it's a maturing community, and till probably not have the same explosive growth it had previously had.Now, ALL that said, if you're talking about net-migration numbers in the single-digit thousands, you're probably looking at too small of a slice of the MSA.

The home had a conventional offer submitted the day we saw it and my realtor, convinced this was the best home on the market for the purposes of getting the FHA loan approved, proposed a strategy that involved an above-asking offer to ensure we had an accepted offer.

We were able to get a home that needed a good bit of repairs with a conventional loan, and they gained a ton of equity in it.

Conventional 30-year thru local bank

If you have no income you cannot close with a conventional lowest rate loan.

Would it be a good idea to still write an offer with Seller Financing in addition to a more conventional offer?

As you become more comfortable and can generate trackable ROI with marketing directly to sellers, you can increase your spend or explore other lead gen strategies like digital marketing + SEO

You can purchase a single family home with an ADU with 3.5% down payment using FHA loan or 5% down using a conventional loan or you can purchase a duplex with 3.5% down. 

I would refinance this loan to a conventional loan in your name (it will give you the best financing terms).

Then refinance the hard money mortgage with conventional permanent financing with a bank.