The title says what I'm asking for. The nerfs to the Oakensoul ring are to balance it for PVP. The ring was in a good place for PVE before the nerf, but the nerfs are pretty excessive for PVE. Think of it like this; in PVE, the ring was for 3 kinds of people.

1. the main group it was made for, disabled players that needed a crutch to lean on. People that can't do harder content in-game due to motor function disabilities, arthritis, or other problems preventing them from performing.

2. the secondary group it was made for, newer players and/or players that just don't like the bar swap mechanic. This is the group of people that needed a stepping stone, a temporary item that can improve their DPS, help them learn rotations in an easier, more digestible format. Without the second bar, you can further focus on learning light attack weaving, your rotation, and getting gear to further improve your DPS. It's a stopgap item that is temporary, and will help this group of players get to a point where they eventually won't need it anymore.

3. the last group it was made for, everyone else. Veteran and late mid-game players that want a fun item that can be used to create easier rotations for less difficult content. It's not used for clearing end-game content for the titles or score-pushing, and veteran players that only want to do that don't even touch this ring, even on live. It lets you be a bit more creative for lower DPM builds for when you want to just do a casual daily dungeon, go around in the world doing PVE, doing a normal trial or an easier veteran dungeon like fungal grotto.

For group 1, even after the nerf, they're really stuck with this item. It still helps them clear easier content (easier for the rest of us), but no longer provides them the support they needed to clear end-game content. For everyone else, you'd might as well do a one-bar build with the Sea-Serpent's Coil now.

The Math (simplified)
The damage lost from the changes to this ring is 25%. I don't mean 25% of the damage the ring provides, I mean 25% of your overall damage potential. It's turning builds that were doing 80k dps into 50k dps, and builds that were doing 50k dps into 35k dps. It also lowers your survivability by 5%. See, by removing 10% crit damage, 5% overall damage, ~200 magic and spell attack, and reducing your ultimate regeneration by 2 every 1.5 seconds, the damage lost is approximately 25%. I've tested this hypothesis on multiple characters, and every time, comparing a normal 2-bar build without changing anything but this ring to another mythic, to the new damage with this ring, to take into account the DPS lost in comparison to live on a 2-bar build, by calculating the % damage lost for all 4, those being the two builds on live and the two on the PTS, then subtracting the results, across the board the loss from the ring alone was between 23% and 27%, averaging 25%. This makes the ring pretty useless for everyone, including the main group it's designed for. It helps them a small amount, but even then, the sea serpent's coil does more DPS on a one bar build than the Oakensoul Ring now in most situations.

Keep in mind, the damage players that aren't in group 1 were doing, at best (this being group 3 being the best of the best that used the ring), was around 20% lower than the top-end DPS in the game on live. The majority that used the ring were in group 2, and they only dealt between 40k and 80k dps at best, which is around 30-60% lower than the top end. This ring did NOT need a nerf in PVE. It needed to be balanced properly with PVP in mind; balancing the two game modes separately.

Solutions.
Let's say ZoS balanced the two game modes separately for this ring alone. They could make the changes they already made, but also leave it the way it was using Battle Spirit. Just make it so those skills become their Minor variants in PVP, and stay Major in PVE. But ZoS does not like using Battle Spirit often, and very seldomly addresses the players when it comes to balancing the game modes separately. They fervently refuse to do this, so I have a solution that does the same thing, while keeping to the idea of the ring and balancing the game modes separately.

Add Major Slayer, Minor Slayer, and Minor Aegis to the ring. This would simultaneously give most of the power lost from the nerf back to the ring in PVE, while leaving the PVP side intact without any extra power creep. This would put the ring right back where it was in the content it needs it for, and not harm PVP either. This doesn't help the ring against world bosses, so solo builds for non dungeon PVE would not get a ton of benefit from it. But it's for helping players do harder content. Overland content is already easy, so the ring doesn't need to provide a ton of help there, honestly.
You might say that Slayer and Aegis are for end-game sets only, and should only be obtainable through trials. However 1. Minor Aegis was added to a non-trial set fairly recently, making that point moot for Aegis and making it fair game as per that argument, and 2. I don't see the point in limiting it like that. It doesn't effect player's wants to get good end game trial gear, since for the majority of players, it's only a stopgap set. Temporary. They'll move away from it as they get better at the game and get those sets. And it doesn't effect the end game at all. No one with the Oakensoul Ring does more damage than a top-end player.