Use only one mathematical symbol and all numbers (0-9) to get a sum of 99

Can you decipher these quotes by Albert Einstein?
Blf xzm mvevi hloev z kilyovn lm gsv ovevo lm dsrxs rg dzh xivzgvw.

This puzzle is for Harry Potter fans. Do you know why Tom Riddle is called Lord Voldemort?

When 99 is considered higher than 100?

What runs around the whole yard without moving?

Can you find the missing piece of the Porsche?

It belongs to you, but other people use it more than you do. What is it?

A game is being played where eight players can last for thirty-five minutes. Six substitutes alternate with each player in this game. Thus, all players are on the pitch for the same amount of time including the substitutes.

For how long is each player on the pitch?

"That Restaurant always remains crowded. This is the reason why nobody goes there".

Can you find a flaw in this statement?

In a science lab, a petri dish hosts a healthy colony of yeast for an experiment. Now every minute, all the yeast cells divide into two. At noon, there was just a single cell of yeast and at 1:22, the Petri dish was half full. Can you calculate when the dish will be full of yeast?