My je just hit 50 today. I have been doing some testing with mining mostly. A couple issues I found:
1. Yes the spawn rate is low at the moment. I believe the spawn rate in live was slightly dynamic to how many people were in the zone.
2. I don't recall CL30+ aggressive NPCs guarding level 1-2 fields. Most of the guardians scaled up with the fields but very few had such a large disparity in combat level to the level of the field.
3. I don't recall getting bonus experience from clearing a field in live.
4. The mining "rings" seem like a new concept, I don't recall those in live. They are nice if they are the same type of roids, dull, crystallized, hydrocarbon, or radioactive.