Just a few minor points, a WML on a long gun is very helpful as it allows maximum control of both light and firearm. Also can allow you to keep something illuminated and still open a door. Yes, a separate hand held light is a good thing.

The light exposes your position. Inside a house, especially one with walls painted re-lo white, there's enough reflection that virtually any light is going to allow you to be seen. NVG anyone?

Light mounts-at least non-metallic ones-should never be mounted on the front sight tower. If you've never noticed, it can get quite hot. I'm sure they refer to the material as "heat resistant" but that may be a highly subjective label.

The multi function light with one switch has it's own set of issues. How exactly does one skip a function? Do you have to cycle through the whole menu to turn the cotton picking thing off? When things get exciting, exactly how to you figure out where you are on the menu? I stuck an extra o-ring under the cap of my some of my lights so I only have a momentary switch. The Streamlight paddles are a good option. The tape switches less so-yeah they work, but wait till you have to buy a new one!