both normal 10 man and heroic 10 man in the same lockout? i know 10 and 25 normal modes share a lockout but do regular and heroic also share a lock? i'm being told that they do but i can't believe people were able to get the legendary collection quests done just killing 7 bosses a week.
No you can't kill a boss on normal and then heroic in the same week. Bosses can be killed once a week and only once.
As for the legendary, 25 man raids get roughly 2-3 times the "materials" that 10 mans do, so its very possible for a 25 man raids to have at least one by now.