My 3 siblings just received their 1099's for 53,300 each.

If you sell to the sibling I imagine you are going to do it on installment sale, so it may be a wash for DTI purposes.If you gift it to the sibling, you must really love that sibling to gift (around a hundred thousand dollars?)

Older siblings reside near Denver also an excellent vacation rental location.

He know that if he wills property to my siblings, the business won’t survive.

The property was inherited by 4 siblings, 3 wanted to sell, 1 got cold feet at the closing table. 

As a kid my siblings and I had paper routes in that areas.

Then once you decide ownership, whether the spouse is included or not or if the siblings want to purchase her share of the property and then divide ownership of the rest.

I recently bought a property using a conventional loan we are living in, but am looking to buy another house for my sibling to live in for a year then turn it into a rental property. 

You were correct that VA and FHA are assumable loans, some conventional prime mortgages USED to be if the bank permitted it, and but FHA and VA, I believe, could only be assumed by an arms length party.....ie son daughter, father, mother, siblings....   

With 6 heirs (guessing siblings), it might be hard to get them to agree.