Ruling Team Galactic's Mars and a few quick questions

[Radical144]

Team Galactic's Mars says,

Draw 2 cards. Then, choose a card from your opponent's hand without looking and put it on the bottom of his or her deck.

So, dose without looking at your opponent's hand mean, looking at the back of the cards or closing your eyes/turning your head and picking one?

Which also brings up the question of when is a player allowed to rearrange the cards he/she is holding?

Also one quick noobie question, how vigorously are you expected to shuffle your cards?

Thanks!

 

[King Arceus]

You basically just choose one card in their hand without being able to have knowledge of what it is. You are expected to sufficiently randomize your cards. So a few times of shuffling should be fine. Make sure to let your opponent cut your deck after shuffling.