I use it with the regular video mic @ 48 volts on Mackie fx mixer

That is correct.

No, this adapter does NOT convert phantom power (+48V) to plugin power (i.e. 3V to 6V) which is what your lavalier requires unless specifically stated otherwise.

Yes, you can use the VXLR adapter with the Deity mic.. The VXLR adapter converts 3.5mm TRS to XLR. Since the Deity mic uses a 3.5mm TRS to 3.5mm TRRS cable and you need TRS to TRS, swap out the original mic cable and use a standard stereo aux cable such as the Kopul CMX-RC30 Right-Angle Coiled Stereo Mini Cable - Black, 8 to 30" (B&H # KOCMXRC30B).

You could use the RODE VXLR 3.5mm TRS Female to XLR Male Adapter to connect a 3.5mm line output to a camera's XLR input, although the signal will be mono and it will come in hot due to being a line signal instead of mic level.

Yes. Thats what I needed it for and it works.

Yes. The following adapter will get plugged into the events mixing board.

The RODE VXLR 3.5mm TRS Female to XLR Male Adapter can be used to connect a wireless receiver, such as the Hollyland Lark Max, to the XLR input of an audio recorder. However, the audio signal passed through the adapter can only be mono.