1. Good breeds for this are style are hamburgs
http://www.mcmurrayhatchery.com/silver_spangled_hamburgs.htm because they dont take much food and will roost to get away from most predators. The breeds suited for this are normally very unfriendly, cant handle confinment, and are poor meat caracasses. You will needs lots of insects and crops to do this. Consider adding
compost piles near them and/or maggot/black soldier fly compostors.Chickens are very destructive, which can be a great help, but if they run out of food (and probably before) they will destroy any nearby plants you have. Good crops included millet, alfalfa, heirloom corn varieties, etc and
http://www.greenharvest.com.au/PoultrySupplies/PoultryForageSeed.html. Fruit trees are excellent and the fruit itself and the spoiled fruit (insects) will feed your chickens. Mulberries are great and produce chicken food for 3 months.
2. If your going to let them free range they will find places to lay eggs out in your garden, however this can end up in stepping on some really old eggs, makes your hens in the field more vulnerable to predators, and means you are less likely to have chicks being raised successfully, plus I'm sure you can find uses for the eggs, or your neighbors would be happy to have extras. So no, but I would definetly build the boxes.
3. Not from hawks and stuff, obviously. I have seen coyotes buy me jump pretty high fences so I would get the extra tall netting if taking this route. However, hamburgs and most of the "flighty", light breeds ideal for subsisting without feed will have no problem clearing anything less than 5 feet I'd say and could probably get higher. I raised large cochins and much lighter hamburgs. The cochins would stay in their enclosure, not going more than a few feet off the ground, the hamburgs would be on the 6 foot chain link, on the barn, up in trees, whatever. A tall (6-7 foot) electric netting fence is very effective for most breeds though and most predators.
4. Roses, bamboo, any dense cover really, is good for the bird, but without locking them in at night and/or livestock guardian dogs this wouldn't even be a consideration where I live because of large numbers of coyotes. Plus chickens like to roam, especially hamburgs.
5. Turkey I've heard yes before, never raised them myself. Quail I hear some breeds are very aggressive and others docile. On a large enough plot you should be fine.
If your goal is patch clearing, if its stuff like new grass, tender greens, etc I would go with geese or ducks and avoid the destructiveness of chickens that needs to always be focused. It sounds like you want free range (from question one) but chickens wil clear what they want, when they want, if not fenced in. If fenced in having no purchased feed would be very tough and they would need to be rotated ALOT to get enough insects/protein. If you dont care about production though nutrition isn't quite as important. Really, the main questions I would ask is how much land do you have that you could allow the chickens to tear up, and really consider if you want to produce eggs/meat. These and some other factors will narrow down what breeds and housing make sense in your situation. Hope this helps.