As for "Iron Vanguard" vs. "Vanguard," the answer's simple. Paragon paths, like PrCs in prior editions, are meant to represent specializations. "Vanguard" is way too general a term (to say nothing of the fact that using it now means the term is unusable for any other related or similar paths later).
I think it's vital for paragon paths to have names that are unique and unmistakable.
That said, while I'm fine with some of the names, I do agree that "battle archer" and "astral weapon" could use a bit of tweaking.