Can't help with the Atty leaking as you have not said what Atty it is.
I'll agree, most people need the Switch screw tight. Safety of KISS - keep it simple Stupid
I do NOT tighten any of my switch pins, unless the mod will fire with it tight in the particular configuration. I also am always aware of switch feel and throw. I also NEVER pocket carry a Mod - with exception of an ego450 w/carto and protective sleeve.
Those are My personal choices and not the norm for most users and I do not endorse going outside the norm.
*You may be getting Switch Bind.
Please do as suggested and disassemble the switch fully and clean all parts.
CAUTION - remove parts slowly and over a smooth clean surface. That little rice pin is hard to find.......if not impossible.