While "Thunder King Rai-Oh" is on the field, you can still remove from play cards from your deck and you can still add cards to your hand which have been removed from play, so you can still activate "Gold Sarcophagus", etc, and afterwards the card will be added to your hand.
Previously Official Rulings
These TCG rulings were issued by Upper Deck Entertainment and have since been deemed unofficial by Konami. They were previously considered official and can still be correct, as long as they follow the official gameplay rules, or unless Konami has issued a ruling that says otherwise. References: