The seller (via the real estate agent) replied that there are no leases - past or present - and that the rents are paid via money order so he has no record.

Here is a catch phrase I say and it takes all that away so you better write this down, this is what I say when I an negotiating with a seller:    (  Mr / Mrs Seller,  I work with a network of cash buyers located all around the country and I would like the opportunity to present it to them for the next ( 30/60 ) days and see if I can help sell this home. 

In the recent months I was presented with a relatively good deal and have been waiting on the owner to clean the property in order to sale it.

Look for someone who can present you per line item basis, and separate labor and materials, then buy materials.

Or does an attorney have to be present?

Always use a price that has been set by the market, this can be determined by using a local agent to conduct a valuation on your home or by looking at similar properties in the area on portals like Rightmove.Condition & presentation.The condition of your property and the way you present it is vital.

I feel that my manager was incompetant to not get a cash or money order for the security deposit before he presented these bad tenants to me and I am so frustrated with myself for trusting him and by things he did, I don't want to pay him any more money.

The event had a Shark Tank portion that allowed participants to present in front of well-known investors and I volunteered.

Some vendors present.

Given that the house costs about 60K, and "looking on it from the side" may seems like a big gift/present (which it isn't)I'd appreciate any advice!