Since the property is vacant and the judge awards me a judgement to take possession am I able to start the rehab process?

Until possession of the unit is returned to you, the original property condition report stands and can be used at end of tenancy for calculating the final return of the security deposit.Inspect the premises now and identify any damages that have already occurred and charge for them.

if you have filed a unlawful detainer I assume you don't have possession of the property.  

The landlord shows the possession order to the cops and asks to have the tenants removed for trespassing.

Seller is out of state, recently came into possession of the property, and is highly motivated, so he agreed to the appraised price.After the amendment was signed and returned, the loan officer called to inform me that the underwriter is requesting some inspections based on the appraisal.

In my state, I am allowed to take possession of whatever was left behind.

Early possession may require the PR to post a bond, which would be an expense to the estate. 

If the buyer defaults on the Note, the owner of the NOte has the legal right to foreclause to regain Title and possession of the property. 

I wouldn't call a probate lead or pre foreclosure lead a niche investment strategy if all you do is buy it in a straight sale agreement.I have some other strategies:Buying partial interestsBuying heirs interests in estatesAdverse possession and gaining title via quiet titleBuying property subject-toStraight OptionsBuying debt to turn into foreclose-able judgment liensI've done four out of the six above.

Possession is accomplished with a lease. :)