Absolutely, positively do NOT do any of those things mentioned without getting an education.
You cannot drill into the hull no matter how shallow the screws are. The sides of the port helm console are not thick enough unless factory installed a mounting pad under the carpet. You may be able to mount up against the bow mold depending on the bow cushion locations.
Under the sole you often have fuel cells, power cabling, fuel lines, a steering cable and stringers that could impede the wire path. It's all bad news under there if you are drilling blind.
You can mount to the sole but not within 3 to 4 inches of the hull. With a changing hull contour and dead rise the sole can get mighty thin at the perimeter. In any case you will want to use pilot holes and drill bit stops to control depth. Where the battery cables come through determine how thick the sole is.
Every boat model is a bit different.