This ended up being harder than I originally expected due to a number of factors, but probably the biggest one was that I had built my business up so quickly and had completed so many properties before I ever filed my business' first tax return.

those numbers would be too close for my comfort. let's say your purchase price is $75k, closing costs of 6k, fix the roof for 5k factor another 5k in other repairs and holding cost while work is being done by the time you refinance for 110k and pay the refi closing costs of 5k you'll have made 14k on the deal, and that will be 6 months down the road.

Consider these:Knowing why it’s an abandoned project is a factor.

That would include down payment, closing costs, rehab, and any other up front costs.Timeline: In an ideal world we’d be all moved in 6 months from now, but we are flexible.

Factor in other expenses (repairs, taxes, insurances. 

I'm sure if you were to ask most investors at which point in the investment property lifecycle they break-even and truly start cash-flowing they either haven't figured that out or don't know how to calculate that number or what the true IRR on a property is going to be because they think once they close escrow with 20% down they are cash-flowing on day 1.When @Chris Seveney talks about the IRR for a long term buy-and-hold, I factor in a rehab at year 15 of a 30 year hold, whether it's due to wear and tear, or possible change in interior styles to remain competitive in the market.

You (generally) are trying to factor in “personal enjoyment” or “personal use” as your upside.

In the book "What Every Investor Needs to Know About Cash Flow" the author talks about not just vacancy but also factoring in rent that you can't collect for various reasons, for example a tenant who refuses to pay but is still living in the property (not technically a vacancy).

Assuming that assigning is not a desired option, what are the determining factors in choosing to use transactional funding vs using C Buyers funds?

Just factor it as a cost of doing businessWhile California deems the LLC is doing business in California doesn't necessarily mean that the fund will have California state sourced income.If the LLC files a partnership return and all the payroll, property and sales are outside California - The LLC will not have any California state sourced income.