I want to do business with integrity and honesty so my name and business reputation will have longevity.

The aluminum sounds good for both price and longevity.

The IRS has seen a noticeable drain of their auditors who had the most longevity and are now trying to cope with mediocre, second string employees.  

. , I always go with tile in the kitchen and bath for longevity and the ability to seal the floor from water damage. 

In regards to your concerns, you should put together an MOU regarding the terms of your agreement with performance clauses protecting both parties, and eventually lead to a JV agreement.There are several other methods to protect yourself as well as the owner/seller, however, too lengthy to write about.Don't be too greedy, otherwise it will limit your relationships and longevity. 

I'm curious to find out the $/sqft for a multifamily modular complex, and what the longevity is.

I've seen enough things fail I've got a good idea on how to put things together for longevity sake down to the wax seals on the toilets.Rents for 3bdrm 3 bath are 1375 ea w no lawn care.  

If I upgrade this building just slight, it will improve the tenants moral and longevity.

The tenants in these areas are C at best so longevity will be an issue, but you can achieve 1%.

Longevity of credit lines, improving credit to debt ratio, paying bills on time, etc.