Well, I use Arrows a lot, and people powershield when your camping. If you use Arrows as part of your combos, they can't really do much to retaliate. Arrows are VERY usefull in keeping combos going and a bunch of other things too. Arrow Looping is a valuable technique too, and I think it's not getting the reputation it deserves. In my opinion, Arrows are really underestimated. They can be used to combo, to keep you from getting back onto the edge, stop an attack, keep the opponent in the air, and so many other things. And yes, using it in midair and for edgeguarding is good too.
-And yes, Down B is really usefull for gimps. It can gimp people such as DK and all the space animals, and Ike as well. And Down B is usefull on stage if people like the Space animals or Ness use their Up B on stage, and it's usefull for reflecting projectiles.
I agree with most of what you say here. We should talk more about this stuff ^__^.