Each tenant living in a building has their own unique rent amount, so even if they do not leave a notation with the rent payment, I know whom paid the rent based on the amount alone.

I have, at my sole discretion, waived the late fee as a one-time courtesy to a tenant whom (a) is in good standing and has paid promptly for at least a year, (b) has informed me in advance that the rent would be late, and (c) pays up within a few days after the late fee would have kicked in.Whenever rent is not received, I start right away with a rent demand letter and proceed with the eviction process on the first day it is permissible by statute, even if the tenant eventually pays (including collection costs). 

Pre-agree on what counts as a “major decision” (sale, refinance, long or large leases, cap-ex above $X), set response deadlines so no one can stall indefinitely, and write down exactly what happens if a partner doesn’t fund (temporary loans at a stated rate, dilution after a cure period, or—only as a last resort—a forced-sale trigger).

He paid on time for a couple of years, so it cash flowed, then he cashed me out.

I paid off all these loans asap with the mailbox money.

Depending on that and how long its been, you could request a refund and just indicate that you'll otherwise have to dispute the charge if paid by credit card.

I suspect the GC you selected wouldn't have been awarded the work if you handled the pre-construction activities.

You may not be aware...but agents get paid when they sell properties.

I have decades of experience real world with it with 100s of pre foreclosure transactions done and in the books. 

I basically did a sub-to and gave the homeowner 2k, paid the back payments of about 4k that my sister lent me and we did a note for 3k more for the homeowner when I sold the house.