They often price it aggressively and then usually wait 3-4 weeks before considering any price reductions.

Assuming that the property is not as described but not so bad as to be more effort than I want I do not pull the offer or give any indication that I will be seeking a reduction in the price.  

Since FNMA will not allow IPCs in excess of 2% of the purchase price, we went with a $1,700 closing cost credit + a reduction in the purchase price of $2,300.

Here are several by Mapie and there are other mfrs out there as well. http://www.mapei.com/US-EN/Tile-&-Stone-Installation-Systems/Crack-Isolation-and-Sound-Reduction

The only reason to use an LLC (assuming you use Partnership tax treatment) is risk reduction.  

So if you could get 0 points paid on the loan, you could still save that point via a price reduction from that seller.The buyer always pays the fees.  

I think most of us would be content building a portfolio of properties that other people are paying for that gives us monthly cash flow, principal reduction, and potential appreciation on top.  

@Jeff White typically the contract rents at the subject will serve as the best "rent comps"  for the subject's market rents; however in this case, where the units are being rented for well below market, the appraiser will not give much weight to the contract rents at all and base rents heavily on other market rents.  

I say that because your house payment will be covered so you can use the money that you would use on rent towards debt reduction or more cash reserves.

Utilization carries a weight of 30% in the FICo scoring models, 23% in the Vantage models.A short credit history will also result in lower scores than long-established credit.For other applicant, yes - the late payments and collection will bring the score down.