Here are my thoughts...
Office and vertigo need to burn in a fire.
de_ali should be tested first, because there's a two of area that tunnel (Long A and tunnels to B), which would make it really CT sided. Also, bombsite B is really small.
de_ruins is big enough for 32 and taking/re-taking bombsite is fair.
de_cpl_fire_ecg_ve is huge!
Add de_cache!
I highly recommend this map:
http://steamcommunity.com/sharedfiles/filedetails/?id=129256732
Yeah, I was hoping that someone would bring up these points about de_ali. My take regarding tunnels to B is that B site (or the general area around B) is divided up into several different corridors and rooms that make the site different from de_dust2's B, for example. CTs are always able to get to B pillar room before Ts do (I guess technically pillar room isn't B site). However, if the Ts can manage to take pillar room, they have a couple of different approaches to take to capture B. It's definitely a bottleneck, no doubt about that. As for A, it's wide open. In my mind, though, this is great for 32 players. A 16 player team should be able to hold that site well with smokes. Although, because this is a pub we're taking about, some people are idiots and run through smoke all the time...
Regarding de_ruins, my biggest concern with that map is player visibility. The map is definitely big, it's definitely pretty, and you're right about the bomb sites. But player visibility is incredibly important.
de_cache was in rotation. Was it removed? This is one of the best maps currently available right now, imo.
And finally, I actually have one more recommendation. de_cortona_pro:
http://steamcommunity.com/sharedfiles/filedetails/?id=139519337. Apparently this was a CS:S map, but I've never played it before. I checked it out with bots tonight and it looks good to me.