For instance, our Rental #3 is not attainable anymore. 

Although I have somehow managed to attain $100k in equity thanks to appreciation, it technically has negative cash-flow after CapEx, Vacancy, and Repair evaluation.

If I decided to purchase and end up separating  into a duplex w/o city's approval, will I have to attain Aurora city rental license and/or will it raise any questions if a rental inspector comes inspect?

If you want to deal with more appealing places then 20% is easily attainable too.

Not sure if this is setting my self too short, but I feel I can attain this with my current skill set and through networking.

You will attain more success when you recognize your role in these situations.Good luck

This is a highly attainable goal that can be reached by a small commercial property or private lending. 

.· For units which do not turn over, above guideline rent increases may be attainable for major building repairs or substantial renovations; however, caps on those increases can lead to a reduction in renovation projects, as the ROI for those renovations is not high enough to justify the cost of renovation.

Thanks BiggerPockets for providing the resources to make success in this industry attainable!

You can mix them to attain your desired risk tolerance as investing in both allows you to dial up/down the downside.