What are your determining factors?

There are several factors to look at before attempting this, the zoning allowance, water issues as mentioned, the neighborhood rent comps, the cap rate, etc.

Are there any other factors when looking for a market that I should be considering?

If the tenant stays for two years, I do not factor in a vacancy rate for year three, etc. until I need to replenish.The capital reserve is ok at 8-10%Regarding property managers, an absolute necessity.  

the great thing with real estate is that the IRS gives you an annual deduction called depreciation which is a non-cash tax expense.The second thing is timing of expenses, the IRS may allow you to accelerate many expenses in earlier years as opposed to over a longer period of time.The third is that many taxpayers miss out of deducting all the expenses - They just write off items that are directly related to the rental(insurance, taxes, interest, etc) without factoring in personal expenses that help your rental business.If you purchase a bunch of cost friendly houses(below $100,000) and are getting close to the 2% rule, then it is likely that you may have positive taxable income from your rentals.Best of luck

If one factor is negative, the other factors can make up for it. 

This cost needs to be factored into your purchase price!

If you don't have checkbook control of the IRA, those are probably the most important factors when choosing a custodian.

These factors, which should continue to apply to the separate entity test under the check-the-box regulations, include—the sharing of profit from the business;the sharing of losses from the business;ownership of a capital interest or performance of substantial services;participation in management; andrepresentation to third parties as a partnership (including the filing of partnership returns, the existence of a partnership agreement).

Other times a cash out refinance will not be suitable is if you don't want to take on additional debt or the new payment will take you cash flow negative.It seems you have a goal of how you plan to utilize the proceeds of the refinance, so that is a good reason to do the refinance, but you will also want to look at all the other factors to make you final decision.Best of luck!