I can offer 10% down with seller financing with a 15 year term and a buy out clause (as described in the calculator) or take out a conventional mortgage with 10% down.

You are not paid by the seller. 

I know never to trust or believe a sellers proforma or a brokers assurances that "this is a great deal"... unless you are the seller and it is your proforma of course *cough*, but what would you say are the hairiest items that people tend to miss?

If the Pre-Auction offer is not accepted by the Seller before the Auction starts, it will be deemed rejected.

Get the specifics of what they are looking for then go out and find a motivated seller whom is selling a property 50% under market value.

@Matthew JohnAs you can imagine, it is highly dependent, market, property and the rent you are demanding.  

A buyers market means that there is more supply and demand so buyers can get the best deals at this time.Sellers market means that its the perfect opportunity for sellers to sell their home.

Any tips on negotiating with a seller who has their home listed far too high? 

I've discovered that:They only work with industrial and/or retail (and seem curious/surprised why I'm investigating apartments)They are the listing agents for properties in the area (it is a sellers market where I live).Being a first time investor, I'd like to have a trusted professional in my corner; using a listing agent (at least to me) represents a conflict of interest.Should I be cold calling firms outside of my immediate locale, such as major cities nearby (or national)? 

There is a lot of property on the market and not a lot of demand.