when the plug is really digging in and fishing properly, the hook should be trailing the lure. in other words, the bill will/ should be the deepest part of the lure and typically touches anything first (such as wood, debris, rocks, etc.). I have had some problems getting the magnum warts hung up in shallow rivers or a magnum bait diver because they dive so deep, but it is much easier to free a single siwash hook than a treble.

when back rowing plugs, they will typically work with the current and avoid snags... well, I would say 50% of the time if you get them in the meat of the hole and where there is actually water flow causing good action.

my theory regarding treble vs. siwash is that a treble is easier to hook a fish when it first strikes and easier to "stick", but you can get a better hold of a fish and better hookset with a single siwash. a treble can only go in so far. and forget about harmlessly releasing a fish that has been hooked with one of those owner ST-31 trebles (which I use for steelhead plugs). often you get a fish with lock-jaw... as a result of having 3 barbs locking it's mouth shut. for spinners, I prefer the weight and action when a single siwash is on. Even in hatchery fisheries where trebles are allowed I do not fish them- it feels weird to me (physically, not emotionally).