If the most recent 20 years is instructive, I expect more of the same. 

I use a written letter that includes my name, contact information, instructions for paying rent, and instructions for contacting me for ordinary issues vs. true emergencies.

Licensed plumbers buy directly from the manufacture/distributor so in theory the water heater should last longer. 

Intel is a great example, who is building the largest chip manufacturing plant in the US right here, and it will be a $20 billion dollar investment that brings a few new thousand jobs. https://www.dispatch.com/story... are a few more recent investments https://www.10tv.com/article/money/business/hydrogen-power-company-hyperion-bringing-700-jobs-to-columbus/530-25907aab-5517-4661-a9f3-d2ed2d5be6b0

The instructions for line 42(a) provide these options: Geological and geophysical expenditures (section 167(h))Pollution control facilities (section 169)Bond premium (section 171)Research and experimental expenditures (section 174)The cost of acquiring a lease (section 178)Qualified forestation and reforestation costs (section 194)Optional write-off of certain tax preferences over the period specified in section 59(e)Certain section 197 intangiblesStartup and organizational costs Creative property costsPublication 551 says this on the bottom of page 2 under "Real Property", subsection "Settlement costs":  "You can't include in your basis the fees and costs for getting a loan on property." 

Intel is a great example, who is building the largest chip manufacturing plant in the US right here, and it will be a $20 billion dollar investment that brings a few new thousand jobs. https://www.dispatch.com/story... are a few more recent investments https://www.10tv.com/article/money/business/hydrogen-power-company-hyperion-bringing-700-jobs-to-columbus/530-25907aab-5517-4661-a9f3-d2ed2d5be6b0https://columbusunderground.com/kaufman-development-purchasing-franklintons-idea-foundry-sp1/ https://highlandcountypress.com/Content/In-The-News/Headlines/Article/Development-projects-will-support-1-4-billion-in-investments-in-Ohio-communities/2/73/77342

Intel is a great example, who is building the largest chip manufacturing plant in the US right here, and it will be a $20 billion dollar investment that brings a few new thousand jobs.

I read a book (Invisible Deal) and it recommended only Working on manufactured/mobile homes that were 1985 or newer.

I have 20+ years experience in traditional (TV, radio, print) and digital (search, social, & display) advertising spanning several industries including retail, broadcast television, manufacturing, ag services, small business, and non-profits. 

Even with property management expect to do your due diligence, and give them instructions.