In a few of the states there is either a form. you must sign or an application that your escrow closer must file in order to exempt from any state taxes or withholdings that might normally be collected at sale . 

When my tenants sign a lease, 99% of the time they have not only seem pics but been through the unit (usually twice).

So you may not NEED a lease signed for your primary residence already, especially since that's a lot of stress to find a new tenant and have a lease in place while you're under contract on another home.

I wish I had known that prior to me signing a contract with an agent.

Incorporate what if you die, what if you or a partner want to sell how do you value, opening bank accounts, contract signing, etc.  

@Brad Smith This one took about a week to get a lead and then another week to show the property to the tenant, negotiate terms with ALE, and get the paperwork signed.

It seems like what you are planning would be in their best interests so I would discuss it with them first and then make that the impetus to sign a new lease and up the rent.

You'll just have them sign the contract so they are locked in with you, and the homeowner doesn't turn around to try and sell the house to someone else while you are working with the bank.

Find a renter, qualify them, move them in, collect rent, oversee repairs, re-sign leases, move them out, turn the unit, rinse and repeat.

But what is really cool is you can get between 1000-10000 dollars in commissions for signing people up who want to learn about real estate.