If the fighter does actually start beating the guy to get information? That's not a move (unless he stops and says "tell me what I want to know or I keep going," that's leverage). That doesn't mean nothing happens! The GM plays it out according to agenda, principles, and moves. Is the guy really willing to die over this?
Is he willing to die for it? He's a hardened assassin, so I'd really want to let a move dictate that.
As for Parlay covering it: Yes you could argue that, and it's not much of a stretch. Manipulating with the threat of violence is a time honored tradition in my AW games. The Fighter, however, is not well equipped to do that by default, and has little mechanical incentive to do that if Str is highlighted.
A Gunnlugger, on the other hand, with Hard highlighted, can Go Aggro all day long to beat the tar out of someone for information (more or less). It was this discrepancy between AW and DW which caused the most questions.
As for XP, I appreciate that the team is looking into it, and yes, it is super easy to tweak that. The main question becomes, then:
Do we keep advancement (aka leveling) constant, like in AW, or do we make it multiplicative, as it is now. As is, it could take a considerable amount of time to advance at higher levels. May a hybrid system is called for, where it's (random numbers) 5 xp for levels 2-4, 10 xp for 5-7, and 15 for 8-10.
As for human's as monster. Human's can be far more interesting than monsters, in a different way. While a giant spider can tie you up in a cocoon, humans are cunning, brutal, emotional, horny, murderous, and all around crazy. Maybe a human guard can't use a poison stinger, or a flying dive attack, but you can bribe the, insult them, or lie to them. And if you must kill them then they need stats.
Do you see DW as capable of settings other than heavy on dungeon crawling?