Good Riddles

Question: I am often known as a symbol/mark, and can be used in a trend. I am created when two paths meet, but separate at the end. What am I?

Question: Mary and jack are newly weds and want to go on a ski trip... So jack starts planning. He books a flight for them to Colorado. When they get there Mary gets pushed off the cliff. There is a guy in Hawaii named Sam and he was reading the paper. He right away said the husband did it. How does he know? HINTS: they have never met in person, jack did not tell Sam, he was not guessing, and it did not say it in the news paper.

Question: A man works at a high security facility. He goes to work in the morning on his computer. He types in his password, but it is incorrect. He remembers that the password changes every month, so he calls his boss. The man says, “Boss, the old password is out of date.” The boss replies, “Yes, the new password is different. But if you listen closely, you will figure it out. It has the same amount of letters, but no spaces.” The man thanks the boss and types the password in immediately. What was the new password and the old password?

Question: If you look at my face there won't be 13 any place.

Question: Some use me, while others do not.
Some remember, while others have forgot.
For profit and gain I'm used expertly, I can't be picked off the ground or tossed in the sea.
Only gained through patience and time, can you unravel my rhyme?