[Dimaz]

1) No way to change attack sequence, however if you put boots of quickness/jade armor you'll be able to strike with 2nd attack sequence *after* def had been reduced. Also I don't know if 2 birds combine, usually there is better use for 2nd misc (luck/ama). Don't know about repel.
2) Never heard about 100% desease, probably there is some mistake here.
3) Penetration only helps with spells cast directly by the mage, not by weapons. So for example you cannot increase penetration for charm crown or ethereal crossbow. I think the same goes for built-in weapons you mentioned.