The regulations will outline all the rights of landlords and tenants and by doing so outline what can and can not be included in a lease.

Have discloses in writing that outline the risks in detail and advise the seller to seek both legal and tax advice. 

I've since learned that it can be done yourself VERY simply as Daniel outlined.

Outline what happens next if they screw you over on being 'Mr.

If you use the "Search BiggerPockets" box at the top of the page, you will be able to quickly find this topic in previous discussions that will answer your question.... just type "red flags".Also, most basic landlording books will have a tenant screening chapter which will outline red flags.

You will also want to put in writing and have tenants sign upon receiving it a document that outlines the house rules and use of common areas.

I do have a thorough animal application/agreement that outlines the rules.  

@David Faulkner and @Michael Swan you have both outlined your end games so I thought I would share mine.  

At least they are letting you know they are breaking the lease and who knows, their situation could change in the coming months and they may end up staying longer.For the future, add an "Early Lease Termination Fee" clause to their lease which outlines the fee they have to pay to get out of their lease early.

Simple stuff.The other option is Johnny maintains his own dwelling and stays no more than 7 days as outlined in clause 123.4 of the lease agreement we each signed.If I haven’t heard back by ____(2 days from now I will assume you’ve chosen option 2 and that Johnny will be gone by ____ (3 days from now) and will confirm this with an inspection at that time.Be well,Your name”