Common locations for supply lines to fail are where male threaded galvanized pipe is threaded into brass or copper valve and fitting bodies  (due to galvanic corrosion)  and hot water lines will rust up so badly as to start restricting water flow or begin leaking a decade or two before the cold side fails similarly.   

As noted by John, issues arise when neighbors start complaining for various reasons.

If not an event, what else could I do to reach out locally to start building these relationships?

To me, the most important contact is your contractor in the BRRRR process, so I would start by securing a good 1-2 contractors.

As I am doing this, can I start to ask my existing tenants to sign new leases with the LLC and make payments to the said LLC or do I need to wait till everything is done. 

So it starts now all this sub 2  and the deals are starting to unwind.

What they said^^^^Zero point in starting off your business adventure with a 'work-around' and potential fights and fines.

Feelings of regret about starting to late.

Hey Jerome that is a question I had at the start as well.

We started off with a 30 year at about a 4% interest rate, but we paid the principal down considerably to about 70k, and then refinanced to the 15 year loan at 2%.