I don't know why everyone keeps coming up with all these convoluted, unnecessarily complex ideas about how to "fix null" while completely ignoring the elephant in the living room.
Power Projection - A term used in military and political science to refer to the capacity of a power bloc to conduct war. IE, to intimidate other powers and implement policy by means of force, or the threat thereof, in an area distant from its own territory.
Power projection in Eve is insanely overpowered. It's completely ridiculous how massive fleets of the largest most powerful ships in the game can also travel across the entire map faster than anything else.
This leads to sov war being a game of RISK in Space with unlimited airdrop rules. All that really matters is who has the biggest teleporting blob because that blob can be anywhere you want it very quickly. More quickly than much smaller, far closer, but purely local forces can respond.
If you really want to fix null, the one thing that must be done is to nerf power projection so the big blobs can't just attack anyone, anywhere, anytime with total impunity and overwhelming numbers for easy, guaranteed wins anymore.
Jump drives on capital ships and Jump Bridges should be removed from the game.
That would make capitals the core of the home defense fleet rather than the fast reaction teleporting IWin blobs they are now. As it should be.
In reality the disadvantages of large, extremely powerful forces are that they're slow, difficult to move, maneuver, support and supply over long distances. They are by no means a quick reaction force. Jump mechanics turn reality upside down and give a massive, unsurmountable advantage to gigantic fleets of the largest ships in the game.
Leaving jump capability on Black Ops should be ok. As a plus they're actually extremely well suited to smaller fleets fighting geurrilla warfare *against* the big blocs and their giant blobs.
Edit: heh, fixed a silly typo, it's "big blobs" not "big blogs".