First question: If you have the crossbow of speed, can you attack regularly with your regular weapon and again with the crossbow of speed, in lieu of moving?
Can you combine the amulet of protection with the blessed shield? If not, why? shouldn't you be able to wear an amulet and carry a shield?
If you attack a monster, can you move 6 squares so you are two tiles away, so the monster can't attack you?
1) A bit of a grey area this one. I've always played as yes, however the rules state you can only attack once per turn. Up to you.
2)You can carry both , but only benefit from one defence and one attack bonus at a time, so you would have to choose one.
3) Yep - this is fine if you can pull it off.