I plan on mailing the letter certified and I wanted to know do landlords also call the tenant as a courtesy to let them know about the letter. 

Horror story #2: while selling off one of the Class C Indianapolis properties, buyer asked me to pay replace the sewer line before closing... absolutely not...here's a partial credit (check to written out to contractor from closing proceeds so buyers don't pocket the money) 

You need better contractors, because "not* putting in clean outs on a full repipe is just dumb, lazy and cheap.

My contractor does great tile work. 

Unless you are confident in estimating the renovations needed, I would highly recommend getting a contractor's professional opinion of the rehab costs.

Also, the ability to find good deals with an accurate budget to complete the project up front from some good project managers/general contractors.

I can say from having taught classes on these loans that your contractor will be the biggest key to your success.

Every thing you read in these forums about rehab, contractor and landlord mistakes, I've done it.

I contacted the city to get all permits and the only one was one that my contractor got that I paid for.

To succeed with the BRRRR strategy, focus on buying properties at a discount, work with trusted contractors, and plan for refinancing timelines.