No, it's about a 1930's mobster in kind of a stylized alternate reality where supernatural stuff is relatively common. Like I said, kind of Sin City with magic and zombies.
Please no. Sandman's, like, five times longer than Watchmen. No way in hell that any movie could even begin to do justice to that comic. You'd need not a movie, not a miniseries, but an entire television show running several seasons to get even half of it onscreen. Especially since it relies so heavily on old literary allusions and tropes which would go right over the head of most Hollywood execs, and hell, most movie audiences too.
I'd be all for that.