I have an applicant that may have a criminal record that was expunged. 

I want to send a notice introducing us as the new owners and giving them notice that in order to renew their lease they first must consent to a criminal, credit, and eviction screening under our new minimum qualifications/new lease terms for all persons over the age of 18 that live in the home and also inform them that rent will be increasing November giving them the chance to stay if they want  and meet our rental qualifications or decide if it's best for them to move.I want to know does this seem reasonable and if there are some things I should consider before moving forward with this plan?

For you to assume it is car theft without further investigation is naïve on your part, are you a criminal lawyer by chance ?  

Criminal and Civil. 

The lease may be terminated in case of any nuisance, disturbance, offensive conduct, illegal drug use, and obstruction of justice for lying to the police officer.

Joseph Bramante zero offense, I appreciate your insight!

Also, in regards to negotiating a deal, I want my first offer to be low enough to allow room to negotiate up to my desired price, but I don't want to be so low as to cause offense, how much give is there when negotiating?

Not to sounds offensive, but everyone's time is valuable.If you are a buyer, you typically don't pay anything to the agent, unless they charge any retainer fee.

Make sure that you thoroughly screen your tenants in the future (i.e. pull a check on their credit, criminal, AND evictions history) and do landlord reference checks on everyone above 18 that will be living in the unit.

Also you have to be stealing power and a criminal if you grow pot, right?