(I guess they wanted me to pay for their food too...)Anyhow, I hired Attorney, and did Discovery, Which the tenants Admitted not paying rent, and provided Receipts of their fixing up...

He's claiming this is discovery work and should thus be billed separately.  

What do the more experienced landlords here do when it seems like every single appllicant that responds to your ads will lie, straight faced too you, with the discovery of this fact after you check and investigate their information on the application?

That is on top of paying the tax from not buying.If you decide not to assign properties during discovery period then you just take the take hit but money is not tied up for awhile before releasing.

@shree @Shree R. the deals will likely come through relationships, direct mail and on-the-ground personal discoveries.

The best discoveries come from asking.  

What I would seeking to discover is not only the type, configuration, location and rent range, I would also be looking for a future investment team member.

Discovery channel's Mike Rowe has made a profitable career celebrating the people who performs the jobs that others don't want to or even refuse to do. 

I would want to make sure that is covered in discovery before moving forward.

This discovery phase happens PRIOR to purchasing the property.