Thanks for all of the great input! Y'all have got my gears turning on some creative options for structure. I just wish I didn't have to work for a living so I could get started trying some of them.

Ewest,
I wanted to see if I could come up with a dense cover to put close the the bedding area for protection of fry but also not be as snag/tangle prone as Christmas trees. We will definitely have lots of kids fishing and my experience is they will hang up 9 out of 10 throws if at all possible. At least my kids do anyway. We are working on their casting accuracy but... I digress.
That was what got me thinking about the large pipe with dense structure inside. But with the info above from snrub, sounds like that is not the right way to go. Im still pondering on this problem. Seems hard to make dense cover snag resistant.

On the deep water cover from bottom to top, would suspended cover in the middle of the water column work? The reason I ask is, first I dont have anything quite that tall. And second, we like to pull the kids on the tube in that area. Here is what I had in mind.

Material:
Plastic 55 gal drum with screw on lid
Irrigation drip tubing - 3' lengths
Pool noodles or other buoyant material
Rope and weight

Open barrel and put bouyant material inside. Close and drill holes at random all over the barrel. Insert drip tubing "limbs". Drill holes in the bottom of barrel, attach limbs, and rope/weight to the center at correct length to suspended. Drill holes in top, attach limbs and a rope loop to assist in pulling up this contraption in the future. Sink 3 in triangle formation at each location. Height would be where the top limbs are 5' below full pond - due to known fluctuations of at least 3' in depth. Each barrel would be around 8' in height and width.
PS-I am an engineer and tend to over think things at times. Please feel free to make suggests or just tell me I'm crazy :-)

Matzilla,
Thanks! As noted above, I have found that irrigation drip tubing is cheap and works great as limbs. The pic of the pvc/drainpipe structure was something I found on this forum. Was just thinking of putting my spin on it for dense cover underneath. I may end up using some trees for transition cover as you mention but do want to have one or two "kid safe" areas. These will probably be around the bedding areas in the back close to the feeders.