Hi, im new to world of warcraft and i decided to chose a ranged caster as my character, but i am stuck in who i should pick, a mage or a shadow priest. I would be really thankful if you could help me to chose one of them, by giving my the advantages and disadvantages of each class. I would like to know:

- Which class is stronger in terms of DPS
- Whcih class levels faster
- If i chose to pick a shadow priest would i be accepted to heal during some instances
- Is an arcane mage better than a shadow priest
- Which are most wanted during raids and end game stuff once i am level 80

Any other imput would defenantly be appreciated and thanks for reading and hopefully helping me chosing my class. Thankyou very much.