That way you are earning a return on your money and also able to learn how these larger deals are done.

The CC fees are all extra.

I applaud anyone that can do both, as it definitely makes some extra cash when you don't have to fork over 10% of your rental income.I interviewed a few PMs in my area, and have had some experience with bad ones.

It is far better if the landlord just lets Tina out of her lease, and accepts Sam as a new tenant.Or, the landlord might let Tina out of her lease, accept Sam as a new tenant, but also require Tina to guarantee Sam's lease for the final six months (using my example) of Tina's lease term.Either one of these accomplishes everybody's goals without getting into messy technicalities that come about with a sublease.Most leases contain prohibitions against subleasing without the landlord's consent.Many leases charge a one-time fee if the tenant subleases, or is let out of their lease and a new tenant accepted.That is because the situation causes extra work and risk for the landlord. 

The property is probably the best in the neighborhood ($-wise), but only due to extra buildings on property. 

I Always advised buyers to count on having to chip something extra in, above the purchase price, in situations like these, and adjust their offer accordingly.

What are some of the pros and cons of throwing all that extra moolah on top of the mortgage payment?

If you're still mid-career and looking to simplify both your taxes and your business structure, I'd start looking into creating the brokerage as an S-Corp, leaving your particular earned commissions in and pulling a salary from the brokerage. 

Or sell and stick it in more funds and earn 8-12 percent passively.

You can gain knowledge and experience while earning a good living and you’re your own boss.