The most important was to test the major systems: my property had a boiler room where all the copper was removed and the HVAC company didn't air test the lines so we found over 300+ leaks INSIDE the complex which naturally made for lots of drywall repair too. 

Most tenants will view "gifts" as a landlord returning a portion of their own money.Most landlords, in support of giving tenants presents, have little to no knowledge or understanding of human nature.

I can tell you for sure that #2 and #4 come natural to me... that is why I do more of that.  

It seems either people can deal with it by their nature, outsource enough of what stresses them to survive, or get out of the business (and then badmouth it to everyone they know, typically.)

Initials: _______Tenant agrees to pay for clearing the sewer drains of the Premises of any and all stoppages, except for those stoppages which the Landlord will agree were caused by defective plumbing, tree roots, acts of nature, or which are declared in writing to have been so caused by the plumber or other person who is called to clear the stoppage.

My analytical nature allowed me to create quick scenarios for a calculated risk. 

The second mortgage would naturally be registered against title to protect the interests of your friend.If your friend extended you an interest-only second for 5-years (or however long until your primary mortgage term expires).  

If you're familiar with accounting basics, it tends to flow naturally. 

@Rickey Garcia I'm in the camp of "go for it," but I say that with the assumption that you'll do your homework before signing any paperwork, you'll have contingencies in your budget, and you'll be prepared to handle the stressful nature of a flip.

@Jeff B. with regard to there being a lein on the title or something of that nature?