I would record my name on the title at the county if I were you. 

Is the contract recorded?

Once I more substantial track record I'll move to 1/3 and eventually 1/2. 

They've been divorced about 10 years apparently.I checked property records and it appears only his name is on the property, even though she is the one who has been paying the property taxes.  

I want to know at what time does the public records gets updated on sites like Zillow, Redfin when the property sale transaction completes ?

In October 2015, owner dies and there is nothing recorded with Jeff Co Probate.

Then you can record your expenses there and it makes it easy for you and your CPA.Regarding startup costs versus expenses, there are plenty of articles you can find on the subject with a google search.

For the record, I'm not sharing my tax returns with any potential buyer.  

Per the CFPB, "Within a 45-day window, multiple credit checks from mortgage lenders are recorded on your credit report as a single inquiry." 

Scheduling a showing today, I read in the listing notes: "You're being recorded."