How many cosplays should I list that I want to shoot? I have a problem choosing since we only know a few of the locations, can I list all I'd like to shoot and have photographers choose or how does it work?

Mostly cosplayers bring 3 cosplays, but it rly depends on ppl. If you think you can manage more, you can. Also its better to decided which ones, since if u left it to photographers, you will be in a organizing hell.
For the locations, check #pixelmania2k18 on facebook. You woll see most of them there.