I see a lot of split level homes that would be perfect for this scenario.

If this were an apartment complex, you would have full rights to camera up the common areas. 

Software is a common question on BiggerPockets.

I would disagree there are a lot of wrong answers in this scenario as someone who puts a significant value to time.

That's a fairly common issue in smaller markets.

Jackson nailed the answer to your first question.A HELOC is a line of credit using real estate as collateral.A credit card is a line using your credit as collateral (nothing).A business line of credit uses your business as collateral.A "PAL" or pledged asset line is a line of credit that uses your investments as collateral.Etc.All of them share in common that they are a line of credit; you draw what you need and only pay interest on what you use.Traditionally, lines of credit that have collateral are going to have much lower interest rates than those that don't, like credit cards, because in the event of default there is nothing to seize.

It is more common to see 80% LTV on rate-term refinances, and some lenders will allow you up to $5,000 in cashback proceeds.

Generally, the further you go from a city's center—about 20+ miles—such properties become more common.

Piercing the veil is very common. 

@Joshua TalamanteIt is actually not that common for Solo 401(k) bank accounts to exceed $250K in cash for any extended period of time.