It's just the resources seem far and few as compared to a Kansas City or somewhere bigger.

Are there any restrictions and risks of renting a SFH for business plus residence purpose?

What made you decide on FL  compared to other markets?

If all units are residential 2-bedrooms rents could be around 1300/month.ARV as a 4-family around 450k-500k, but there are not a lot of comparable from the past two years sold.I wouldn't be able to finalize how many units/uses I would put in until I know how I would refinance. 

This property cash flow to current value is not great (because its value is so high) but the cash flow compared to purchase cost places this as our best purchase. 

That way we can compare what the selling landlord is telling us to what the tenant has to say about lease terms and catch inconsistencies before closing. 

Also I have 10k for a down payment, the house is only 50k and comparable homes in the neighborhood that are in decent shape but need an update are selling for 100-140k so it would be a great investment but I’m looking forward to hearing some insight from people with experience in this sort of thing.

It worked well for me because I was a busy running a business and my local market was not good for passive cash flowing REI, as prices were too high compared to rents.Yes you do own the property. 

What if a new building makes your investment property obsolete because there’s a better facility with comparable rents?

You can't set it up just for purposes of qualifying for a Solo 401(k).Also, if you contribute to your day job's 401(k), you can still contribute to your Solo 401(k), but the total contribution limit ($18,500 for 2018) is the max for both plans combined, not separately, meaning that it's not $18,500 for your day job's 401(k) and $18,500 for your Solo 401(k) but rather a grand total of $18,500 for both.