you had on the blizzbreaker, surgebreaker and blazebreak sets. I like it!

I like that ideas. Most of it.

Firecracker, Cold Snap and Static Flash
Need to be careful with those - there is no pure elemental sword. Which means, in contrast to DBB, those bombs would easily make the game more imbalanced unless further changes would be made (like p.E.: make DBB and the new bombs deal less damage than nitro in addition to the lack of knockback + make piercing swords deal split like all other swords).

Cautery Sword
Me thinks this sword is a lost cause. It either needs mechanics different from anything that's in the game now (p.E.: a charge attack that deals insane dmg to jellies and to those only)... or to to be left alone... or to be removed from the game (possibly giving all players that own one the chance to exchange for a different item or to get a "broken cautery sword"-artefact as reward with unknown future possibilities).

Ionized Salt Bomb and Radiant Sun shards
Has still some balancing (+general "usefulness" :P) issues, but those wouldn't really get worse if a 5* existed. So... just adding one shouldn't be that much of a problem, should it? Just complete the f'in line already, you can fix it later! ;) xD

Blizzbeaker, Surge Breaker and Blazebreak
Noone needs those armor sets, but then again, noone needs most of all the armor sets, so completing those lines shouldn't really be a problem. Also: The bonus damage that you propose would be a neat future feature except for one problem: enemies in lvls where you would wear this armor are mostly immune aganist the element because they can inflict it. Otherwise you wouldn't wear the armor ;). So: if anything, make it bonus dmg against [elemental type], e.G. all mobs that inflict fire, not all mobs that are set on fire.

Winmillion
Exactly. Why not? Not much of a problem here.

Searing and Static Edge
Those mecha-swords are neat, but not really thaaaat unique. I think there are enough elemental swords around (for now. Other niches need new item first.), and enough of them 3hitters. If anything, those swords should be connected to the respective brandish lines. And to do that, maaaaany big changes to the game would have to be made first (like p.E.: make it impossible to get good UV's on 1* equipment + more likely to get good ones on items with more stars).

The Ghost
Can't see why not. You could balance it out exactly like DA <-> fire brandish <-> FoV with Acheron & GF. Need something to waste almirian seals for, make it cost 200 pls ^^. Not because it's powerful (should be balanced ;)), just because it's "cool".

Awesome Vitasuit (Name still in work)
Yupp. Also balance those against heart trinkets. They're useless otherwise. I see some difficulties with players wearing all the +hp stuff 5* together in lockdown, so I think a penalty that hurts in lockdown (more than in the clockwork) would be adequate for this armor. Like to shock & ice resistance and/or walking speed.

edit:
Oh, we forgot the shields.

Swiftstrike buckler:
There, I'd suggest somerthing sort of similar to what has been done to the mercurial set. Make the "high" bonus exclusive to the 5* version, make the 3* low, 4* medium. (2*: nothing, if there needs to be a 2*). Basically that would mean, the new 5* version would be similar to the 3* version like it is now, just slightly better normal defence.

Scarlet Shield:
See vitasuit ;). Increase health bonus. Add various penalties. Maybe negative ASI, lower defenses... which could give it its own niche as a "bomber shield" for occasions where ASI is not needed (and you can't use your shield half of the time, anyways).