From the day I turned 18 I began creating credit for myself to make this happen. 

It also leaves nowhere to add Person D.I also don't want to create a lease that just runs from April to June because that would give Persons A and B a chance to change their mind at the last minute and decide to move out as well in June.Thanks for any suggestions.

There is minuscule chance, an average Joe who wants to be successful in Real Estate, other than borrowing money from family, having many friends, raising capital via syndications, creating a Corporate Entity, ( which necessarily don’t impress me, there 100 unit apartments, over leveraged, I could do in my sleep!

Does not matter - if you have a different EIN - you should create a separate QuickBooks file. 

Work on creating a buyers list so you can avoid this problem.  

I’m seeking advice on how to effectively create an offerand structure the deal.

There are great services out there that assist in marketing your property, creating online applications and screening your tenants for you. 

In those cases or other specified large rent increases that cause displacement, landlords would have to pay relocation benefits, with increased benefits for the disabled, seniors and those living with minors.The measure would also create a nine-member rent stabilization board to determine annual adjustments, hear petitions for individual rent increases and pursue remedies in court.

I am in the process of creating an LLC or LLP for my company that will start buying tax lien certificates.

Several people I've spoken with suggest creating a relationship with your alderman or knowing the right lawyers who specialize in zoning that can help expedite the process.You also want to consider if it makes sense economically.