1: Move the damage synergy for Frost Nova to Shiver Amor. Only Shiver Armor should be a synergy for Frost Nova, but at the end Frost Nova should have the same amount of damage. Shiver Armor synergy should be Frost Nova, not the other armors. This makes much more sense than making Blizzard and Frozen Orb the synergies.
2: Give the 3 armor skills a synergy with Warmth. Each point in Warmth give the Armor +1% Faster Cast while the armor is active. Thus, a max of 20% Faster Cast. This makes sense for a max Warmth build as you are casting faster so you want faster mana regen. The idea here is that it makes sense for some Cold and Fire skills to have synergies with each other. Things like the cold armor allowing you funnel warmth sucked from the enemy to empower yourself to move faster.
Those two changes will give us three types of Nova Sorceress builds. First, you’d have the classic Nova plus Energy Shield. Second, you’d have the dual elemental spec with Frost Nova and Shiver Armor plus Nova and synergies. Third, you’d have the 20 points in Warmth, 20 points in Frozen Armor, plus Nova and synergies - this version being focused on more flexibility in faster cast equipment due to having 20 points in Warmth.
3: Move the damage synergy for Enchant from Warmth to Blaze. Warmth does not work well with Enchant, you don’t need mana regen on a sorceress hitting things with a sword. You don’t have to cast Enchant often enough for mana regen to be an issue. Blaze works much better as a synergy, because faster run walk helps make the sorceress more combat capable. You can also use Blaze with Enchant on a bow, run away and then shoot the enemy as they walk into your flames.
4: Move the damage synergy for Blaze from Warmth to Enchant. Warmth does not work well with Blaze for the same reason. Blaze and Enchant also make sense as synergies, since one spell is enchanting your weapon, and the other is enchanting your boots.
5: Add synergies to Enchant from the armor skills (Frozen, Shiver, and Chilling) to give +1% Increased Attack Speed. Theoretically this would mean a max of +60% Increased Attack Speed on Enchant with 20 points in each armor type, but with the needed 20 points in Enchant synergy and 20 points in Fire Mastery, you can realistically only get up to 40% increased attack speed.
6: Add synergies to Blaze from the armor skills (Frozen, Shiver, and Chilling) to give +1% Faster Hit Recovery. Theoretically this would mean a max of +60% Faster Hit Recovery on Blaze with 20 points in each armor type, but with the needed 20 points in Blaze synergy and 20 points in Fire Mastery, you can realistically only get up to 40% Faster Hit Recovery.
There, now you can have a more viable melee sorceress build.
Further improvements to melee sorceress?
7: Add synergy to the armors, for every point in Enchant, add +1% Increased Chance of Blocking to each armor (while active)
8: Add synergy to the armors, for every point in Blaze, add +1% Faster Block Rate to each armor (while active).
9: Add a Monster Flees when hit effect to Inferno. See if that makes a difference. A big problem with Inferno is you can’t run away while casting it, so why not make the monster run away. It would also give Inferno a utility effect. I doubt this change would be enough by itself to make Inferno viable, but I’d love to see how much effect it does have.