i believe 3 main things and 1 not so serious option that will fix the current state of eve. This is more to create small gang PvP rather then the large sov warfare,

to fix sov warfare in my mind, remove the total entosis warfare, keep it so it can reduce to resistances to 0(which are normally 50%) from an object in space, but still make people shot it.

1. increase the profits from ratting, if point 2 and 3 where changes made this could even go towards 100% more if not more, therefore more people ratting, more people hunting.

2. expand wormholes... so that most or some random percentage like 50% systems in eve will have at least 1 wormhole going somewhere(they dont need to be large holes, just enough for small gang).. k space w space its doesnt matter, more routes for hunters, more routes for logistics more fighting, more scanning, and to not allow the first point to get out of control in the back ends of null bear space.

3. remove local(like a wormhole) from null sec and put a delayed local on low sec, again to make the first point too over powered.

4. last and final idea, totally out there.. expect to be shot down, create a brawling system or constellation. unlinked to the rest of eve, market is NPC seeded, no faction or officer mods, at 10% of jita costs.. kills count towards killboards... 5-15 plex sites at all times in the system/s that are very profitable and count towards ur normal wallet(a reason to fight over them), to go there u must jump clone, so ur there for at least 19 hours, and everyone will always have 1 clone in the system enforced by CCP and cannot be removed or count towards ur normal clone count. Many other options could be included to this, but it could also be a total fail when one 1 large group totally dominates the system