Although in today's market sometimes the seller stipulates that the buyer pays closing costs.

FHA, VA, and other loans do have residency requirements, but there are usually stipulations for change-in-life circumstances.The real question is if it's actually a good financial decision to hold this as a rental.

When I purchased my first home on contract, the contract stipulated that any deviation from the contract was to put me in default, the same as if I stopped paying.

The laws that I am aware stipulate we have to make a reasonable effort to find new occupants.

Or what stipulations do you think I need in a contract?  

Our lease stipulates that if anyone not on the lease agreement who is staying more than 7 days in a month we are to be notified of this individual and who allow us to do a background check.I confronted the tenant about this boyfriend and that he has been there more than 7 days (eyewitness from neighbor) and that we were concerned. 

Another thing I add is a drug use stipulation.

The Safe Act and individual state requirements, as stipulated by Dodd-Frank, all make the issue very complicated. 

The within 6 mo stipulation is for the "delayed finance" guideline.

Check with your agent but here are a few items that should be placed in the special stipulations portion of your contract (special stips will often control over conflicting stips in the contract which is why you want to put them here):- Due diligence starts when the Seller delivers to the Buyer the bank approval letter- Earnest money is due within X number of days from the time the Seller delivers the bank approval letter (BAL) to the Buyer- Closing shall take place within 30 days of the Buyer receiving the BAL- Buyer may, at Buyers sole discretion, terminate this contract if the sale of the property is not approved by the Sellers lender within 90 days of the Binding Agreement Date.