[vj]

You will be able to feel the weight of the putter better without grounding it. At times people will in fact "bury" the putter head in the ground before taking it back...very bad.

Having forward shaft lean or de-lofting the putter at address will have many effects: The loading of the shaft will feel different, the hinge will feel different, the face will appear to point different at address, the left wrist and right wrist will feel different at impact, and the ball will be hit above the equator in a descending blow.