1. There are ways but some gankers use PG & Solo to mat collect etc so they arent actually in Open all the time.
2. Some gankers will take each others bounty, thats why its capped at 2m Cr, sending 'they got killed' messages seems ok at first but its not, its potentially harassing type behaviour or witch hunt mentality, it doesnt lead to good places.
1. I'd say the tracker becomes available when the commanders with notoriety are in open and in non-Anarchy systems (You want somewhere for them to hide).
2. As I already said, drop the reward for notorious commanders. Either that or make sure that no-one on the notorious commander's fiend, squadron or wing list can't claim the reward.
3. I can't see how that can be categorised as harassing type behaviour (considering some of the behaviour of the gankers), it just a small bit of feedback to let you know that the bounty, which your death created, has been collected.
4. BTW, None of the above should apply if both victim and attacker were pledged to different Powerplay Powers.