Defense skill completely ineffective against ranged/magic/alchemy, right?

Just to clarify,defending against non-melee attacks does not give you the defense bonus on activation, correct? It seems that i get no benefit from blocking arrows/magic bolts with my fists. with a shield it does seem to reduce ranged damage a bit, though this may be from the hidden shield stat bonus for defending with it. Not sure if blocking magic/alchemy with a shield helps at all.

No, I'm pretty sure defence still works against archery and magic even without shields, so long as they don't knockback. If you have a shield that means Magnum Shot will also not knockback. I don't have much of a say in alchemy, though.

Blocking Magic doesn't reduce damage though, because all these intervals only affect Physical damage. I have no clue about Alchemy though, but considering most of them ignore Defense...

If you consider negating the stun from the hit as defense "working",then that's true I guess. What I mean more is the defense and protection bonus from defense doesn't seem to work without a shield. I get hit with an arrow, then i get hit with another arrow for about the same damage while blocking without a shield.