In other words if you buy a rental property in an IRA and use leverage (debt) - portion of such income derived from leveraged portion of the property (minus deductions) will be subject to UBIT.

Similarly using the high point in appreciation to derive an expected appreciation is also a folly.The average appreciation this century for Oakland is just under 5% (Source NeighborhoodScout). 

The Solo 401(k) also has the advantage of being more favorable for real estate investments using debt-financing such as a mortgage - as the 401(k) is exempted from a small tax called UDFI that an IRA would pay on the percentage of income derived from the borrowed money.So, as you continue your research and get feedback here on BP, think about what type of program will best suit your needs and be sure to ask questions along that line.

When HELOC lenders calculate debt ratio, they take what your starting rate will be on the loan and add 2% to it to derive the qualifying debt ratio.

Most do not even know what it costs to replace a hot water heater on a weekend.So your rule is a way too aggressive derivative of the 1% rule. 

@Brock Barr  I think there's a large segment of the investor population that derives physical pleasure from analyzing properties but then will suffer physical and emotional torment when it comes to actually doing something.

The overwhelming number of real estate investors don't have the faintest idea how an appraiser will derive their opinion of value.  

In the derivative market regular investors buying calls while the bank is selling the premium and keep hedging.

Robert Kiyosaki illustrates it best when he said "currency is derived from current, as in moving water.

Don't use % for capex and maintenance, these costs are derived from fundamentals and tenant base.