Always have reserves after the purchase of an investment property and vet your tenants well.

Both of these options (selling or raising rents) will benefit you - it is truly up to you on what would make the most sense - raising rents will definitely drive up your cash-on-cash return on a monthly basis but selling would also allow you to acquire a large sum of money that can be used for new construction so that you can maintain your current reserves.

-utilities (I have seen some things about having utilities reserves.

Typically these are reserved for single-family properties but since they're the highest leverage you can get they can put you in a good cashflow position if you're willing to make two units or rent by the room.In terms of looking at 2-4 units, the sweet spot tends to be 3.5% down on an FHA loan for a duplex.

If you plan on canceling the reservations have the current owner cancel them on THEIR account. 

Also there is another factor that is easier (and likely cheaper) to have 1 reservation at a time on the property. 

I'm using a flat 8% for maintenance and 8% for capex reserves and 5% for vacancies.  

Sounds like if I were to go ahead and invest in a larger multi-unit I need to prioritize setting up a solid team and ensuring I have plenty of reserves before engaging.

The Federal Reserve holds tremendous sway over interest rates which in turn can affect home prices.

A lot of them have no reserve and are living paycheck-to-paycheck like most Americans.