The Heart of Gold late puzzles

Hint: How can I get a decent cup of real tea?

Hint: How do I stop the Magrathean missiles from blasting the Heart of Gold?

Hint: How can I collect all the Fluffs?

Hint: How can I grow the fluff tree?

Hint: How can I get into the closet past the screening door?

Hint: Now that the screening door is open, how do I survive the gloom?

Hint: How do I leave the HOG to go onto Magrathea?