I am not an admin, but I know the answer to some of your questions.
1) Hiring players ingame to kill others is not explicitly against the rules but there are certain parameters that must be met; generally only certain IDs can be hired on the spot by non-generic IDs. This post covers this, but after reading your post and checking the rules, bounty rules one and four are contradictory and would probably benefit from a small update.
2) Faction right six states official factions may pursue individuals who are using their ships and/or technology without permission. I have queried this in the past and while bounties may be Sirius-wide, I have had admin statements clarifying that engagements can only occur in the faction's zone of influence. I personally believe official factions should be able to engage tech thieves Sirius-wide, but that's for a thread of its own.
3) I think making ships outside their zone of influence be dead for more than two hours is a good idea. Two days is maybe too extreme, but four hours or even 12 might be a good change to the rules.
4) I think this is also a good idea and support it. SRP IDs should also all be unique and list their restrictions so they are easily accessible to others by scanning the ship.
5) This is still the rule. Player base names and IFFs are permanent. Locations can be changed under special circumstances such as system redesigns and mining field changes, but this is rare and conducted on a case by case basis.
6) Unless I'm missing any, generic IDs are freelancer, pirate and miner. Bounty Hunter, Zoner and Junker IDs are not generic.