how to add/ edit a move's effects in gold?

[Hexx17]

in my gold revamp i changed alot of moves using a tool (gsc attack editor) , but if the effect is different from the original effect sometimes it break things. like if you add damage to sand attack then the accuracy drop doesnt work. or like if i try to make hyper beam have ancient power or tri attack's effect then it doesnt proc. how do i fix this?

or is there a way to change a move's proc chance? for example if i dont want mudslap to have a 100% chance to do its effect.