If I am not able to secure financing, I will lose this deal.

Private equity backed by a promissory note is considered a “bond” which is considered a "security outside of my broker/dealer's control” which is a big no-no if I am registered with them.

Think of all the things that could go wrong and see if the lease addresses them: unauthorized pets or tenants, early termination, security deposit, lease violations, late rent, eviction, lawn maintenance, parking, etc.5.

It seems this may be a difficult expense to estimate given that it is not entirely clear what will be included in a property's "repair and maintenance costs", but maybe some of you have a rule of thumb or method to help you estimate these expenses? 

Most of these homes are very poor locations and very poor condition.You need to hire someone to go out, access the property (drill out locks, install new locks, and install lock box with keys,) clear the property (many of these properties have squatters living in them,) secure the property (lock windows, fix broken/unsecured points of entry,) evaluate the home, build a rehab budget, and send over pictures and/or video.There are several GC's and home inspectors who are offering these services for the MI/OP clients.

If you're interested in learning more about finding your niche as a real estate investor and options for marketing methods, I wrote a whole book on the subject. 

I prefer to give the BRRRR method a shot.

Your money needs to be secured by a note against the property, that note had better be prepared by a lawyer in the state where the target property is and it had better be recorded.

Essentially you would not have any real involvement but full transparency can be provided so if someone could offer a guarantee on a secure turnkey rehab solution, would an investor be wise to take up this opportunity. 

I will adopt your method.