Good Riddles

Question: A man is found dead on a Sunday morning. His wife calls the police immediately. The police question the wife and staff. The wife said she was asleep, the cook said he was cooking breakfast, the gardener said she was picking vegetables, the butler said he was cleaning the closet, and the maid said she was getting the post. The police immediately arrested the murderer.Who was the murderer?

Question: My first two are male, and my first three female.
My first four save them both, and my whole is a female of the same sort.

What am I?

Question: I do not eat food. But I do enjoy a light meal everyday.

What am I?

Question: If you're looking for something sweet I know what to do.
But if you don't like heat I'm not for you.

What am I?

Question: If a mountain climber climbed up a mountain one day from midnight to midnight the next day and does the same thing the following day when coming down the mountain, would there be a time at which he was at the same position on the mountain both day?