Wilbur Wright said "Trying to learn to fly by observing a bird is like trying to learn the secret of a magic trick by watching a magician."
They just do it too subtly and well for us to pick up the 'trick'!

I've noticed the tilting of the tail, too. On the model we're flying, however, all the roll control is by the tip feathers. The angles involved seem to create more drag on the downgoing wing, rather than the adverse yaw you get from ailerons.

Regarding the forward sweep on the inner part of some bird wings.....maybe it doesn't serve any purpose, aerodynamically, maybe it's just a result of how the wing is 'constructed' out of the assortment of arm, wrist, and finger bones nature had to work with? Stephen Jay Gould, the evolutionary biologist, said that some traits (like nipples on men) have no functional significance, they're just artifacts of the way things develop...