Undersolved questions in Doctor Who

What is Tuggo? - "...to go."

What did 10 say on the beach to Rose? - Among other things, "Rose Tyler". If you are referring to the instantaneous biological metacrisis Doctor, among other things, he whispered something to Rose, the content of his vocalising is unknown.

Why would anyone want to watch Doctor Who? - It's quite interesting.

What is time travel?

Why did the Master support Israel in the End of Time? What was Obama's plan to fix the economy?