In gateway would it be legal to lift the game pieces from the bottom while they are in the gole and put another one underneath it? Also if you did that would it now be legal to remove the top piece?
No, this would not be legal, as per the updated version of <SG9>. Once a Scoring Object is Scored under Clause 1 of the definition of Scored, it cannot have its value changed. A similar question was answered here, where you can find a full quotation of the rule: