Hello @nobody,
The sound it’s an easy fix, just follow Tim’s instructions:
GSE Pause / Wait: Stop Wasting Multi Charges Abilities - #8 by TimothyLuke
If the other modifiers are not working, you have to unbind the keys for that either manually in WoW or I think there is an option within GSE options you can choose to do that for you also.
Regarding null, not sure I understand what you are trying to accomplish. If I think what you are trying to accomplish, can try a cast sequence null with a reset attached to it for X amount of seconds. That way it will only work once and after X amount of seconds of not using that macro it will become available again for use?
Let me know if that helps or I can help you live tonight around 10pm EST Live on Twitch.