Yeah, sorry; in comp it's usually a common term to use heavies to refer to the heavier classes, ones with more hp and damage--soldier, demo and heavy, usually--and is normally just the soldier and demo since those are the ones in the cookie cutter line-up.
I mention that the rollout might need health added to it because, if I remember right, there's really only one medium health pack that the demo can really pick up and still be relatively fast to mid, if there was another health pack that a soldier could pick up, it might be better. Idk if you'd be able to do a gunboat rollout on this map because of the health pack placement, for instance (not that every map needs one, though, I guess) but I'd have to let some jumpers look at the map to really be sure.
Edit: And the sight line should be p evident from the demo, as it's about the only vantage that the sniper used at mid. Basically it was from the middle door to mid (the door that leads to the water entrance, to the other side of the mid. If you'd still like a ss, I can get you one later.