Is it possible for me to remove the thing where it does not allow hacks when a server says -hax? :/
How do I modify the client?
No. You can't. The reason that is there is so you CAN'T hack on the servers that don't want to allow it. Nobody here is going to help you try to use the World of Minecraft client to hack on a server that doesn't want to allow it. IF it's even possible. Go play on a server that wants to allow it, and stop trying to break rules.
We have a big enough headache with things like lag and a delay with map update, that can leave you standing at the edge of the world, or waiting for our chest to turn from stone to chest etc without having to worry about you hacking around the server.
Connect through a tunnel/proxy, and have the tunnel remove "-hax" from the name/description.
WoM Coins: 1714
Without modifying the client, its impossible