Also, when it comes to the number of connections per IP, don't worry about a user taking over your server. Those connections will close once they are finished connecting. The purpose is to have enough connections available to the user so they can view your pages the way you want them to view them.
There have been times when I had many users on at the same time and the total connections to my server were way over a 100. The unused connections will close but will be available again for the user in case they are needed needed again.