As a wholesaler, what are the pros and cons of dealing with an investor that has traditional financing? What are some rules of thumb when in this type of situation? Do I deal with these type of investors differently than an investor using a hard money lender or another means of financing?  

And is this part of the “qualifying the buyer” process? If so, what is the best way to deal with this type of situation as a wholesaler?

@Brandon Gamblin absolutely is is a qualifying question.  With traditional financing the wholesale fee must be paid by the investor. The financing will not cover the wholesale fee. That can kill a deal.

If you demand a high enough earnest money deposit (EMD) and you make your contract NOT subject to financing then you are covered if the buyer can't perform. With a well written contract you can keep the EMD.

Now that does not address the fact that you may be letting the seller down, since you are not able to perform. 

@Brandon Gamblin Traditional financing will also take a lot longer as well. You need to make sure you negotiate enough time for the buyer to be able to close with a conventional loan.