Various questions, since I'm new and can't find the answers!

1. Gear--should I keep it in case I level other classes or keep it to give to retainers? or is it better to convert it and sell materia? If I get rid of the gear (selling or converting), are there enough other places to get gear for leveling other classes once I've done all the actual quests?

2. Level 40 Leves at Camp Bluefog--but level 49 mobs in the zone? What's up with that?

3. Can you change class when group is ready in duty finder? If I'm out mining, can I join the duty finder and then change when a group is ready?

4. In the duty finder, do you only get grouped with players from your own world?

5. New character leaf symbol--how long does it stay on a new character?

6. When I do levequests, is the speed of completion bonus based on when you complete the levequest, or when you actually turn it in?

7. Gear durability--if gear is not 100%, do you take more damage? Can you let gear get down to 10% before repairs or is that a bad idea?

Thanks for the help!