Loft as a listening space?

It can be made to work, but IMO/IME listening in a nearfield arrangement will work best. If you like a nearfield set-up then it can be great. There are a lot of advantages to this type of set-up.

Smaller speakers required, smaller amp required, less room interaction (certainly in your case).

By going to a nearfield arrangement, much of what the other posters are stating with regard to the room issues become more mute. The idea of the nearfield set-up is to reduce, restrict or eliminate the room boundaries from the sound. A recording monitoring studio with a nearfield set-up is a good example of this.

Can you eliminate the room, not realistically, but taking this approach properly can get you a long way there. I would not be scared to try this and think that you can get good sound in doing so without killing yourself in the process.

With those speakers, a nearfield set-up could be very nice. Not sure how your sub will integrate though. Since it is not a point source, you may find the sub to be the problem. Although, you may also find that the sub isn't necessary in this arrangement - try it both with and without the sub turned on or connected. The sub, I think will either become over bearing as it will try to fill the room and then feel slow and sluggish due to the room size. On the other hand, if you keep it toned way down, it may get lost altogether in this space. I would even be tempted when playing with the sub to place it closer to you, perhaps just behind you, keeping it toned down. By having it closer, you may be able to lessen the volume of your space be getting a more direct impact from it. By having it just behind you, may also expand the soundstage to the rear to some degree (I know this isn't exactly natural for a set-up), but I once listened to a friends Martin Logan Summit set-up and he added a sub to the back of the room. The affect was pretty nice - albeit a completely different setup that the OPs.

Steakster, so have you played around with anything yet? We'd be glad to hear your results and what you found worked best for you. And of course, what proved "fatal".