if you're so worried about having to play on a script, this should assuage you.
I've never played a Hitman game before, and from seeing gameplay I'm sure there's a lot of "video game things" that bother me (like the disguise changing) but it's so plainly obvious you can tackle these missions like six different ways depending how you approach it. All but maybe 5% of what I saw in this Quick Look was totally different than how the lead designer demo'd the game for IGN earlier this week, and they played the same level.