Brushes aren't visible from the inside, people...
@Ant: I assume that's going to be a back-alley?
I think it's time to give some comments on the version I played (well, ran through). It's late, I know, but hey.
Well, the map looks great, that's for certain. Nice style, maybe a bit too 90-degreed but not as bad as I expected. I like the architecture and the sunny feeling of the map.
I've got some things about the layout though, and that's those small canals to the right of the library, when seen from the water. They don't seem to furfill a purpose and are essentially dead-ends. Besides that, it looks like a very close-packed yet open layout. Might be a good thing for fast action, might be less for tactical play. Well, I don't play CSS so I'll leave that to others.
One thing I had rather seen is the use of canals for actual gameplay (besides fitting well with the Venice theme, they also make interesting situations because water makes noise...). They're much more Venicy than streets (I love that little plaza in front of the library though) and bridges would be nice too. Probably too late to throw it in the actual gameplay but you definitely should put those into the background.
All in all, a small but good-looking map. I hope it turns out well and becomes a fun-to-play map, then you've got it all settled. Keep it up!