The reason I ask is Iv been bounty hunting around Cubeo all day today and Iv noticed a few ships from Zac Hudson and Sirius security, all have been wanted. I killed one and my fed rep dropped slightly so I wouldn't fire on the others. If I pledge to a power will I be wanted in other power's territory? Also, am I now wanted in Zac controlled areas for blowing up one of his ships? I'm friendly with fed and imp.
If you log out, your reputation reduce over time. If you than don't do missions for the federation or empire it goes down to 75% cordial.
Shooting their ships because of powerplay pledging just speeds up things. But i don't think you can fall below this 75% cordial through shooting federal agents. I do this the complete day long and stay at this level.
Once you are pledged to a power, all other powers agents will hunt you everywhere. So be careful where you are. I tryed for example some bountyhunting for an engineer in alliance space (i am pledged to aisling) and these annoying alliance guys were interfering me nonstop. Problem here is, i wasn't allowed to shoot back because otherwise i would be the wanted since it's their space^^
Can be annoying sometimes but i have a small hint for you, only controlsystems and exploited systems are infected with agents. If you wanna bountyhunt in imperial space without get annoyed by these agents, look for systems in these bubbles that are not affected by powerplay
There is also remaining a bug:
If you shoot an alliance enforcer in a federal controlsystem while being pledged to imperial superpower, it counts as undermining and you will get merrits for doing so.
Also when you are pledged to Aisling, and shoot a federal agent in a controlsystem from Lavigny, it counts also as undermining her system.
The behavior that you get attacked from other agents of the superpower is already fixed. (You got attacked by zemina guys when pledged to aisling for example)