Constructive kept me strung out for over a week, submitting doc and after doc after doc, only to tell me at the end, "Well, it doesn't look like you have enough liquidity."

Cool to see that you're from Birmingham, I'm originally from Chilton County!

One being that I personally needed liquid resources(cash).  

So when considering your entire "capital stack" I think it is worth opening up a HELOC on your primary residence to make your equity more liquid, whether you end up doing another house hack or staying in your current home forever. 

B) The pros and cons of having two properties instead of one (especially in terms of liquidity).

All factors that could indicate the economy is cooling down are NOT, in fact, indicating that the economy is cooling down.Can you afford the property at the current rates you will lock in indefinitely or would the payment eventually crush you? 

You will have to get the alderman on board (politics..) and then the neighbors about hours and parking..It's a cool project, it feels like you make an impact on the community, but I would only do that if I had too much money, nothing to do with my time and looking for a proper challenge.

When rates are high you can charge higher rates, offer short term loans (12 months) and have some liquidity and make a decent return

For your first deal I would reccomend having about 50% in cash or liquid assets. 

It's a great place to store your cash until you find the right opportunity that works for you plus all the other benefits it provides (not least of which is flexible terms and liquidity when you DO find somewhere to invest your money).