New Smoker - ECB w/ Gas - Wood placement? Soak?

To start with I would think you will want to wrap the chips in foil, and no soak.
Soaking wood does absolutely nothing more that delay the smoldering which is what you want, not a lot of steam before the wood begins to burn.
Not sure if adding charcoal to the lava rocks is a good idea, it may work but I do know they would be a pain to clean.
My first smoker was a Brinkman Electric Gourmet so I placed wood chunks directly on the lava rocks.
Never used propane anything so as far as that goes I couldn't help.
As for the water pan, you could always just remove that for additional room and place a small aluminum loaf pan or anything that will fit on top of the bottom grate and use that as your water pan.
The ones that come with the unit are quite excessive.