Misc: Whose epitaph says On the whole, I'd rather be in Philadelphia?

Questions

What according tho Edward Young and headmasters the world over,is the thief of time?

Which minister traditionally lives at no 11 Downing Street?

Where Robin Hoods bay?

Who carried out the first manned orbit of the earth?

What kind of boat,invented in 1898 is held clear of the water by underwater wings?