These broad rules of thumb make for fun blog posts, but are too general to apply in practice, and every deal is unique.  

I've read a few books and forms about the basics but nothing practical.

In fact I was happy about the whole thing (not about being told no, but that I forced myself to just 'try').I'm looking at this seller/house and situation/experience as practice.

typically shingles will run you $20/bundle (3 per 100 sq ft or 1 Square) for lower end, install depends much on tear off and prep or shingle over and prep, we have opted for Steel when ever reasonable to do so, it costs about 10-20% more up front, but will out last me, and does not have Ice damming problems we see with regular shingles in the north. standard shingles, you can expect about 1/2-2/3 the stated warranty actual life span, so 40 year shingles will last about 20 years, but steel, even 40 year has been known to far exceed the 40 year warranty, I can typically get a roof done in steel with a 2 layer tear off, and steel installed for around $4-6K for a 13 Sq roof thats material, labor and disposal, I just has a 11 sq one does with dimensional shingles (steel wasnt practical) for $2,700 including tear off and disposal. keep in mind, the cheap guy may not be the best value, there are a lot of hacks out there, and anyone with a pitch fork, a hammer and a nail gun calls them self a roofer. 

When the final room becomes available he rents it out within a day. this is not in a very safe part of my town but people are choosing this type of rental because it's cheap. he also told me he's currently converting an area in the back of the house into 2 more rooms so he will have an additional 900 per month in about 2 months. this situation financially just seems too good to be true. what am I missing or maybe I'm not missing anything and it may be 100% illegal. 60k mortgage not including down pmt, 15k remodel monthly rental income of 2700 and soon to be 3600. utilities can't to huge because I work nightshift everyone else is Dayshift so during daytime hours there are practically no utilities being used. sorry for the long post if you have made it this far.

How do you go about finding a closing attorney or title company that does double escrow or double/simultaneous closing?

You need to go meet with a lawyer in your jurisdiction who practices asset protection.

Be careful, use good business practices, and keep going forward. 

The others are good as well but they just don't have the volume so you'll get less practice but if you are adopting an all of the above strategy, you'll get your reps in.

I've got a lot of theoretical knowledge but little practical knowledge so need to dive in and get my hands dirty (potentially very dirty heheh).If you don't personally need any work in this area, please keep me in the back of your mind if you run into anyone else in your travels who might need something repaired.