Are you doing fix n flips, real estate development projects, or both?

There are, non-bank, investment property lenders that will lend to you based on the property's income (long-term rental loan) or your experience for fix & flip / rehabs.

We have two options as I see it (since I want to keep this in the family).  1) Find a long-term tenant or 2) fix it up a bit more and do the short term tenant thing that is exploding right now.  

If they do, depending on what they are and potential cost to fix, maybe you can implement an increase while lettIng them know you‘ll fix some things you would’ve fixed any way if the tenant had decided to leave.

Do you think it will make sense if one of my partners were to move in and then sublease the other rooms out to pay the rent while we fix up the rest of the house to get it ready to possibly sale or rent out as a whole?

I would say that the model he teaches works in Colorado....but I suspect the market there is even more competitive than here in Texas. 

(My guess is: no).Next, do you have a Lender who'll refi an investment loan for 30 years fixed, at just 5% interest?

if you are a beginning rehabber, this is a deal i would avoid, (unless you have experiences in other related areas or have researched this extensively or have asked experts i.e. structural engineers for their input), as 1) you don't know the prices your contractors would charge2) the estimated rehab costs are lumped under general categories (i.e. concrete, plumbing, electrical), but do you know which specifically/exactly you need to fix?

With fix n flip loans, debt and income is not a factor.

Than a lot of patching and fixing wall cracks and primering the walls.