I haven't seen on but you can actually tell the differences between these things just to correct that signature campaigns is one of the programs inclusive on a bounty campaign.
Theres no favoristism. Period
If a manager or certain camp do need Jr. member and saw your post quality is good then you might be hired but if not then you would be rejected.
No, you can join only one and you can join up another if the current signature campaign of yours is already finished.
Theres no such level