or would u generally interpret that lease language as meaning late fee applies starting 4th itself (which is what I have communicated to him in the past)?  

Always make sure your contracts are assignable for tax purposes (we use a form paragraph added to the contract, consult a lawyer for appropriate language), build in a study period and have contingencies laid out for release of documents and financial records of the property. 

He added that language because we are not interested in doing additional work.

I own the duplex and have language in the lease that the water/sewer charges will be split between the two units.

You will find a lot of very confusing language in most commercial leases with insurance language being some of the most antiquated language in existence.  

The following non-recourse language is listed: The obligations of Borrower under this Note are NON-RECOURSE, and in the event of default by Borrower under the Note or other loan documents, lender will look solely to the collateral securing payment of this Note for repayment of the indebtedness owed by Borrower. 6.

The estimate included language that any unforeseen items discovered that led to overages would require written notification, a new signed agreement to that work, and payment up front. 

It is okay to wholesale in Oklahoma, but you have to find the closers that will assign contracts, many do not.https://www.ok.gov/OREC/Contract_Forms_and_Related...take a look at some of the forms that are used in Oklahoma, mainly "Residential Sale" get to know that and the language used, after that you can trim it down/make it your own. 

They should be easily located on line by searching    your state landlord tenant regulations.I would strongly advise not having your tenants sign a term lease , leave them on a M2M lease to allow you more flexibility, same language as a term but without you being locked in. 

PM me if you'd like me to send you a copy of the language we use.