You are have your answer concerning enabling and disabling tabs. Concerning the first part of your question you can not dynamically change the names of tabs at runtime. The reason is that logically tabs are enumerated with the tab names being the enumerations. In other words the names aren't properties that you can change, they are part of the datatype.
Now what you can do is use a combination of buttons and enabling/disabling controls to simulate the appearance of a tab control - which might not be a bad idea given the problems that tabs can cause.
Mike...