Thus, my taxes should be higher because of the income I generate.If I pay off the primary, I'll increase the amount I'm able to save monthly not having the mortgage, while also keeping the income generation lower on the rental because the mortgage remains open.Any thoughts would be appreciated! 

:Class A Properties:Cashflow vs Appreciation: Typically, 3-5 years for positive cashflow, but you get highest relative rent & value appreciation.Vacancy Est: Historically 10%, 5% the more recent norm.Tenant Pool: Majority will have FICO scores of 680+ (roughly 5% probability of default), zero evictions in last 7 years.Class B Properties:Cashflow vs Appreciation: Typically, decent amount of relative rent & value appreciation.Vacancy Est: Historically 10%, 5% should be applied only if proper research done to support.Tenant Pool: Majority will have FICO scores of 620-680 (around 10% probability of default), some blemishes, but should have no evictions in last 5 yearsClass C Properties:Cashflow vs Appreciation: Typically, high cashflow and at the lower end of relative rent & value appreciation.

If they had not moved out, i would have brought in the best attorney available and charged the tenant for the legal costs.  

It may sound nice to pay a 6% management fee but the extra fees can add up to be more than the other company that charges 10% with no additional fees.

A colleague recently closed on a 12-unit property in San Antonio and shared that a 6.8% cap rate, combined with lower property taxes, made it a no-brainer.

Fannie May is a good option for a lower downpayment.

Most folks are charging 10% of the rental rate for monthly PM fees. 1 months rent for a leasing fee and couple hundred for a lease renewal.

Should I charge her a prorated amount of the original rent or the increased month-to-month rent for January?

That way your purchase price will be lower and your debt will be cheaper due to inflation.  

Smaller house cost, lower loan costs.