With electronic signatures though, this should not be an issue......loosing a deal because of that sucks

Require money deposited directly into your business account, electronic payment through a provider, or even cash at the door if you want to go that route.

Collecting money electronically is great.  

All of the above options would allow you to electronically transfer money without using checks, and are free for both you and the landlord.

Prior to leaving, the guest wrongfully accused the homeowner by stating the owner invaded his privacy by entering into his room in his absence and also somehow electronically interfering with his electronic devices and trying to hack him.

If so, should these be contracts signed electronically or in person?

You could also bundle this service into property management software that services all your needs on one platform: Applications, credit/background screening, electronic rent collection, document storage, and maintenance requests.

I would set up some form of electronic payment so they can actually pay you as soon as they money appears in their account. 

An electronically transmitted Tax Sale list of the delinquent parcels will be available for purchase by registered tax buyers at a cost of $250.

Promises are worth less than the electrons used to send them to your inbox.