"¿A ti te gusta viajar a menudo?"
Translation:Do you like to travel often?
Adding the a ti puts the emphasis on the you. Just like including the tú in ¿Tú bebiste toda la leche?
No, it isn't, but often is there. It's one of those quirks of Spanish.
Nope, not really. Of course, I'm not fluent enough to tell you when exactly a native speaker would include it.