This process is called probate.So when someone says my XXx left me YYY in their will, it does not mean that the person will actually get that item. 

Tell them that their rent due as of today is $xxx including all the late fees and won’t be considered paid until it’s all deposited.

A late fee in the amount of XXX shall be levied on the X day of the month if said rent payment has not been received in full by midnight of the day prior.

"So, like, I just bought a fourplex in XXX.

(Zoning can be changed but it does take some money and some time).SO, for example I find out about a sale of XXX acres in the county next to mine. 

Tenant C and Tenant D will be vacating Apartment X on Oct. 7, 2018 are required to pay the pro-rated amount of $XXX on Oct. 1, 2018. 

If it were me I’d let him know that you reviewed the lease and per the lease terms, he owes $xxx.

I know flippers sometimes write penalty phrases into contracts ("must complete by XXX or pay $/week/month").

Hi Dmitriy I had two options:1-lend to allow them to pay back original investor, which would be interest only payback including capital at end of termor2-equity position whereby I put up $xxx to allow them to payback original investor (no interest paid on lent money) with equity income (rental).I chose option 2 for the income so it would be part owner.As with previous deals (Mortgage Notes) my IRA was on the deed and a promissory note was created as a result of the lending with a mortgage.As I read your questions and write in response I am now wondering if this is typical.

The way you're phrasing it is a little confusing.It would help everyone who is responding to you greatly if you lay out your actual numbers, e.g.xxxx  Rent Revenue(xxx)  Interest Expense(xxx)  Insurance(xxx)  Property Taxes(xxx)  Mgmt Fees(xxx)  Lawncare/repairs/maintence(xxx)  Advertising(xxx)  Tax Depreciation(xxx)  Loan Costs Amortization(xxx)  etc-------------------------xxx/(xxx)  Projected net taxable inc/(loss)