Well, Tibia 11 Protocol woud be probably hard to do and, for that, be expensive. I wouldn't take it. xD~
About advices on code, I think there are already many discussions of OTClient within the OTClient repositories.
I don't know, honestly, what would be necessary for you to do.
But, in my opinion, I think you could make the UI and a small preparation (like automatically set the IP).