@Psyrius aim maps are generally just a way of people shooting at each other across a dangerous "no man's land". Most of the time it is specifically for rifles, occasionally allowing awps and pistols, but usually on their own for balance sake.
There isn't any "meta" to consider, it's a way to warmup. If you want to sit and camp on an aim map, fine, but that's like watching TV with your back turned to it. All the official DM maps are just reused defuse maps, unlike a game like HL2DM, but then that just reuses chunks of HL2 as the map without any real thought into gameplay or flow (afaik).
If you want to take the map seriously as a defuse map, there are a lot more people willing to talk about it and you'll stand to learn a lot more conceptually than just practically for making the map with the tools.
Good luck.