Prior to the webinar I mentioned, I had been self teaching myself to trade in the stock market, which wasn't going too bad.  

It's a nice touch to contact them prior to you having a deal. 

And double closing is frowned upon because you knew of someone willing to pay more before you bought it.What you can do is form an LLC, get the short sale under contract under that LLC and if it looks like it is going to close, sell the LLC prior to close.If it doesn't close you can re-use the LLC.

Find a reputable real estate agent and set up an automatic notification system to email you properties that meet your set criteria right off MLS...this is totally free.The only thing I can extract from your post is that perhaps you need to have a pre-qual letter prior to making an offer?

Starting in traditional notes first prior to tackling NPN even at your experience level is telling.

I also don't check prior landlord references since if I had a bad tenant that I wanted to get rid of and I got a call for a landlord reference i would give a glowing reference just to ensure they were out of my apartment.  

I believe the recapture applies even if not claimed in prior tax years.

as off market deals get harder to come by in my territory:I want to start learning about purchasing preforeclosures ; negotiating the purchase of bank owned properties prior to them hitting MLS ; etc.I want to use RealtyTrac.com to do the above :Does anyone have advice on how to purchase in the above manners ?

Many that you analyze in Florida will be underwater and the bank will not significantly discount below current actual value, and many will be cured by the homeowner just prior to the auction. 

Does anyone know of the easiest way to check for all liens on a property prior to purchasing?