If you have a W-2 job, 1) you rental income gets added to your income and gets taxed at your marginal rate2) if you have a loss, and your AGI is below 100k, you will get to deduct loss up to 25k against the W-2 income ( this is where the tax saying comes in). 

Looks like you may have get a taller base board and shim/block the back of them.

MLS) then probably no value can be added 2.

Just write an addendum removing the departing party and adding the new tenant. 

If my low ball offer is accepted, and I end up spending a total of $5-7,000 (adding in extra for labor and any surprises)  on repairs, with an estimated monthly income of $650-700 in rent, and yearly taxes at around $1,000 I'm estimating I could make a pretty decent profit, according to my math it would pay itself off in less than 3 years.

HELOC is just a credit line, So you can buy/rehab and refinance with a regular loan in order to pay back your HELOC if you want or pay back the HELOC with time.Depending on the type (1% Payback or Interest Only Payback) if you borrow 80k, your monthly payments would be $800 - if you were renting for say $1000+ and covered all expenses, then you could just pay back your HELOC and if rates adjusted, your payments is still 1% payback - you would just have more interest added on for the life of the loan.I have a HELOC and opened it up to be able to fund my rehabs or have extra $ to close on a deal.

Even if you could save on SE tax the added complexity of an S Corp vs tax savings in the scenario would not be worth it. 

Final Note, my area is about 20 minutes from downtown St Louis across the river here in Illinois, investors from STL are picking off properties over here adding further scarcity.Just hoping to spark a discussion that might help me and others - where do you find your good buys?

It frees up time for you to do/focus on other things, and begins the building blocks for you to potentially scale your system easier, build more relationships, and could snowball into new deals through the partnership you'd have with the property management company. 

You will not add much value to many of these houses by putting in a new furnace, replacing the roof, or adding windows but they will kill many years of cash flow.