
wow your way out in the ocean, I actually checked it out, right near Madagasgar, which I only heard about from from the cartoon movies and seems like a cool place, well at least in the cartoons.
My wife ran a cafe that had internet access for the patrons, it all depends what there used to and what there going to use it for, where she was it was 99% windows users, so they stuck with windows, but if there used to linux then go with linux, it's better anyhow
As far as linux mint for the users, yup no problem there but I would go with the main edition, cinnamon.
As far as servers go, I am not sure if Clem has a server edition or not, but a lot of others do, and linux and servers go hand in hand, most servers use linux now and have for some time. It's just all around better.
The reason I say to use cinnamon is because probably a lot of your patrons might be used to windows, and maybe not so much linux, gnome 3 and unity might thrrow them off a bit where as cinnamon still has the normal feel to it most are used to and it wouldn't be hard for any window user to use it.
Counter Strike I'm not sure about, I stopped being a gamer years ago, but if you want to run any windows games, wine can usually do the trick, with a link on the desktop or a separate menu built for games.
As far as patron usage goes, some might want to gamble online (all depending what your going to allow or not) and some will want to download the online casino's software, (they only work in windows and will not install in wine) but most have a flash version now so they can do it online now instead without downloading anything, makes it safer you as well.
You will find a lot of them will want to download stuff so you will have to keep your eye for this kind of stuff, having linux prevents a lot of it from happening, mainly because it just will not run on it, unless you can set it up so only admin rights can download anything, but then some do save images so maybe an account folder for users to save there stuff in so you can go clean house once and awhile, we usually did this mess at the wife's store lol, and it can become a pretty big mess, which is why limiting them to a folder for downloads makes it easier for you, other wise it'll be all over the place.
Make sure you restrict usage because they will get nosy and snoop around.
Do you know any good Internet Café Manager for Linux? sorry nope. Google might be able to help you with this one.
You can also create a intranet/internet set up a php base with mySql database for users a start page and login for users, it can also time there usuage when they log on and log out, when it comes time to pay the bill, it's all recorder in the database, just call it up make a simple calculator out of javascript or php to make a bill up or give you total cost etc...... been awhile since I programmed in php and mySql but it doesn't take much to learn it all.
This way you can create a splash page also and a gateway after they login which starts the time, there's a lot you can do with it, all depends on your cost and time to do it all and how much knowledge you have to achieve it.
Sam