Maybe your market is different but in the national markets I've worked in over the last 25 years, it's not the first and best option.What I've seen more often is that even when it starts out great, the reality eventually sets in, and tension starts to grow, when they go from being the stewards of their own castle, to the stewards of someone else's castle.I'm happy for you that your experiences were different.

Even though he is your father in law, it can't hurt to put terms into writing just in case tensions rise in the future. 

Apparently the two seller's are exes and there is a lot of tension between them and they can't agree to anything. 

It will prevent any tension between tenants/roommates because you can displace the authority of ownership to someone they don't know and they'll just view you as the middle man.Brandon talks about this strategy in some of his blogs to prevent unnecessary confrontation.

Lots of tension, distress, etc.

No splits, profit shares, etc.It keeps it clean and simple and keeps you in full control of the investment.I think payments being paid on performance / profit splits can lead to tension in the family and limit your control in a deal.For instance, if you were going to sell for a loss, and your parents disagreed, or vice versa.

It has small prongs protruding from a short flat section in the middle, which you place against the side of the window frame, the two curved "wings" will be facing the movable window, and when you compress the wings in order to let the window down, the tension will hold the window in any position.

That's where I feel the most stress and tension.

He also relieved the tension a bit.

I agree - there is usually a "locking mechanism" type thing - try raising the window & snap it out - then look in the channel - there is probably something in the shape of a C or U depending on which way it is turned.....this usually controls the tension rod.....play with that & then make sure they are both locked back in place parallel to each other - then re-insert the window & try it...That in itself may work....