This wouldn't work in PVP, but imagine a counter-operative/ Left4Dead Versus style game mode where 3-4 of the terrorists in Terrorist Hunt were players?
Would be even more intense/nightmarish...
In my experience, the other maps are more open. In the beta last week, the map near the boat on the pier had some actual open windows in the buildings. So a few times we had proper long-distance shootouts. And also the map was over two buildings - so once you began shooting, the terrorists would leave one building to come look in the other, and you'd start having skirmishes across the map.
Also there are a couple more modes in the full game - including hostage protection/extraction. Presumably these will include more play across the maps.