There is too many things involved that can easily go unproven in court and the OP being good friends with the owner probably wouldn't be a good enough reason in the eyes of the courts if the kids sues.Definitely get an good attorney and get it done right.

In addition to converting the attic into a bedroom, we're replacing the attic stairs so that the room is easily accessible like any other upstairs room would be.

Make sure you don't have any large expenditures that are not easily explained before you get your loan.

In the Bay Area, software developers are easily clearing $100,000+ directly out of college, on salary alone.

It is also worth noting that if you charge above market rent you will often attract tenants that can't be normally be accepted at average rents, in addition you are more likely to get tenants that will move out faster if they can easily get a better deal.

Kinda puts me in the hot seat.

I got good solid info, once they stopped selling the next level of classes (we weren't sold anything last weekend), good connections to local people, and access to databases of info not easily available to those of us not already in the industry. 

You can easily come up with some images to give you an idea on how it should be framed.

And a way that will easily provide me with a lifestyle that I could have never achieved any other way.......Heck.

Your CPA or real estate attorney should be able to answer this for you pretty easily if you give them the figures.