Consequently, I look for the property to be vacated before I take possession.

If your offer wasn't accepted then the check would probably be in the possession of the realtor or realtors office.

Making great acquisitions requires time and skill, and some people don't devote the proper amount of time or don't possess the proper skill. 

I know at first my girlfriend couldn't rationalize all the work for just "$200 per month".My girlfriend wasn't initially on board either, but her ultimate dream is to someday own an art studio where she prints and sells artwork.  

You don't close unless the seller has moved and left the property vacant of all personal possessions.

Normally you would after the 60th day and you don't have possession, post a notice to them and proceed to eviction.

We've got a whole bunch of stuff to throw away, but also a whole bunch of stuff like books, furniture, tools, artwork, etc, that I think is worth money and could be sold.for those of you that do trash outs, and I'm guessing most flippers do, has anyone ever gotten down to monetizing the trash out process?

I'd send that letter prior to settlement, I'd give possession prior to closing in the sale contract (where you can give your down payment as earnest money) and prolong closing as reasonable, like 90 days.

Your contract gives you equitable interest in the property but you don't have physical possession yet.

Ours is to loan to a few handfuls of experienced flippers with enough business for us, who understand what they’re doing, and who possess the integrity to do as they say.