It's been a year since I've done this, but if memory serves this is what I did:

1. They like the house and fill out an application.
2. I run a background check.
3. I decide to rent to them and they sign the contract.
4. I usually charge a deposit fee, first month's rent and if the contract starts in the middle of the month and they move in at the start of next month, they pay for those two weeks up front.

Contract starts when signed and payment starts then.  I don't take anyone's money until there is an executed contract, unless it is an application fee.

When I did property management, I would take a processing fee with the application.  The security deposit was taken when, and if, the application was accepted.  The rent wass due on whatever date wass agreed upon, but before possession.  The lead time you mention may be a policy to allow lead time period to verify funds prior to possession.  Each property owner has their own policies but must follow the jurisdictional law.  

parked and reading - have not dealt with this in years

It is customary for a processing fee and a deposit equal to one month's rent be collected with the application. The deposit is returned if it is not accepted. The first month's rent is due prior to move in, and is collected after a lease is signed. It is important to have tenant representation by an agent, or to be very diligent not to fall prey to scammers. Your brokerage should have procedures in place to follow when representing tenants and landlords.

Yes, as soon the lease is signed.

What a great question and answers!

in order to secure money needs to change hands with an executed contract if I am representing the landlord.

It depends on what the landlord/agent want for the lease.

Big chunk of cash long before moving and without a contract.

Are they asking you to send it via western union to africa too?

No.

In my State we cannot write this type of contract without a property managment designation.

I would not pay the deposit and rent prior to having an executed contract.  From my experience you pay an application fee.  A credit and background check is completed.  If approved pay the deposit.  When the home is ready for move in, pay the rent.

This is very good question.

The terms of the lease should define when the deposit is due.

As an agent, I would first get an executed lease agreement and then have the tenant pay the deposits to the landlord or the property manager.

I leave that to our property management dept....I do not like marketing rentals....on occasion, I'm "saddled with one"....

Your follow the terms of the lease.

I am flexible and open to discuss this and more. Give & take done correctly gives good results

Listing agent usually collects a fee with the application for the credit check, etc. Rent is due at or before move in along with security deposit (could be around 1 month of rent or more depending)