The big issue with a lot of these items is that the items that they upgrade from are probably designed to not have upgrades. A lof of these just feel like a bit of an unnecessary upgrade to previous items without too much extra going on.
Adding a small extra effect to an upgrade that mostly just copies the previous item is not that interesting and should only be done with items with very simple effects or ones that focus on stat increases.
(ex.: Extra Spirit -> Improved Spirit / Extra Stamina -> Stamina Mastery works because it's primarily a stat upgrade)
(ex.: Mystic Burst -> Tankbuster works because tankbuster is more about the 8% true damage than the 40 extra damage)
For Spirit Nuke: Even if you changed something like Spirit Nuke, it would have to compete with items like Mystic Reverb or Spirit Burn that offer similar burst damage effects with extra added debuffs (Which is what I think a Spirit Nuke remake should do)
For Megaton Force, I think any item that pulls the enemy towards you is an instant no-no for me. Bebop's hook is one of the strongest abilities in the game and I think it shouldn't be made into an active item at all.
For perseverance I'd prefer if the insta-heal passive was an active instead, having such powerful effects depend on such a long timer feels very luck-based when you really need it to kick in during a fight. Just like Spirit Nuke, you can consider an item like Colossus to be kinda like an upgrade with its sutain increasing ability.
For Graceful Curvet, I think turning Majestic Leap into an offensive item is actually kinda cool and the extra hop ability on kill could make for fun plays, but that's also what makes the item not work for me. Majestic Leap is primarily movement based so having it deal damage is peculiar.
For Blazing Eruption, like isleafon already said, the item feels kinda like Scourge already and an upgrade for Torment Pulse would probably be Scourge anyways so I don't think the item could even have an actual upgrade.