She couldn't get the property sold because of the lease land and some title issues.

If you have language in your lease regarding this, or something has been established in the landlord tenant code, you should be fine, if not, lesson learned 

I rent my basement And I did signed a year contract but my tenant keeps bringing people over to spend more than one night, leaves garages open, leave front door unlocked when she leaves the house. can I break a lease without getting a lawsuit ?

If it coincides with the lease on the 1st that is best.

So no need to conjur up a relative lease or create a business unless you want.

If its a multifamily then the average utility cost should be factored in when determining rents at the start of the lease. 

If I close a deal via a subject to deal should i rehab it before assigning a lease option to it.

We have staff; we can draft leases and do evictions when necessary; and my husband, brother-in-law/office manager, their retired father and a staff member are experienced In building/repairing.

Is that the angle to take or start talking about a lease option? 

We had a tenant for 2 ½ years, He was the only person on the lease, but in the application he put his son who lived there till last December.