@Saurabh Kukreja I would start by reaching out to realtors and PMs in those areas to see whom you can build a relationship and depend on.

Not sure what to say about any potential theft, but easiest way is to have it shipped to the cleaners house or you go and personally restock once a month.The potential theft is likely not significant on a yearly basis and if the cleaners are doing a good job and you are making money then I wouldn't lose sleep over it.JohnI totally agree with you, that as soon as I am making money, occasionally missing some items will not be a deal breaker for my business or my relationship with cleaners.

Are all relationships good and open?

A lot of variables here but would recommended getting in front of a lender and trying to build a relationship. 

Looking for a consultation and to just establish a relationship with someone as it’s needed.

Building solid relationships with agents is one way to find the best deals.

I will have probably established a good working relationship with my GC & crew and so I imagine they'd be more comfortable & confident working with me on future projects.

REI is more about relationships than anything else.  

Also, agree 100% with @Bjorn Ahlblad renting to family/friends can be fraught with issues and ruin relationships on top of it.  

I know I had a pre-existing relationship with these folks, however, the important underlying lesson is that forming and maintaining trustworthy relationships is extremely important.