You earn the titles for Modern Warfare 3 by doing various small challenges, such as killing 10 people by blowing up cars. When you complete a challenge at the end of the game, the game review menu will show you have a new title.
No you don't lose your emblems and titles
Yes, you can.
2 or more
Your face thats the answer
They do nothing besides earn achievements.
Modern Warfare 3 is not available on the Vita and there are no plans to bring it to the Vita. Activision has said that there may be future Call of Duty titles available on the Vita.
Modern warfare 3 is better
The intervention is not in modern warfare 3. Modern warfare 2 has the intervention.
Modern Warfare 3 is not in 3D.
All titles and emblems you have unlocked and anything you have unlocked with prestige tokens.
All titles and emblems you have unlocked and anything you have unlocked with prestige tokens.
Modern Warfare Mobilized(the DS port of Modern Warfare 1) & Modern Warfare 3.