I'm working on Spiritbonding gear while I wait for dungeons, and I have a few questions.

1. Goes each piece of gear have a numerical value (ex. helm has 1000 points)
2. Does each mob give varying amounts of points?
3. Does level matter? (Higher level filling gauge faster)
4. Does spiritbond depend on EXP? (IE A monster that gives 2000 EXP fills spiritbond faster than a mob with 1000 EXP?)

Could I travel outside one of the city-states, tag a bunch of mobs, and AoE them to death, would that charge my spiritbond, or only monsters that give EXP?