So, if we look at the Sorcerer mastery, it gives us mana, several bonuses for casting expensive spells, the class spell (meteor) is very mana costly. It looks like the intentional design for the class is having lots of mana and spending lots of mana. But if we look at the mastery passives there are ZERO nodes that help getting mana back! This is major inconsistency that has to be corrected. Everyone uses focus to help with expensive spells, but focus is not class-specific, the tree doesnt augument it even a bit and - more important - focus casting is very disruptive for the arpg that LE is. It looks more as MMORPG skill, where you have plenty time to stop and rebuilt your large manapool. In LE Meteor may cost more mana than you can have!
My suggestion is to introduce few passives that help with that. One will affect a) high manacost spells, and another b) channeled spells.
a) Casting a spell with manacost over 40 to 70 gives you an Elemental Storm charge. Each charge provides 0.2 manaregen per point per second for 10 seconds. Charges can stack. 10 points passive.
Follow-up passive: Each charge of Elemental Storm provides 3% of maximum mana per point on expiration. 3 points passive.
Follow up passive: If you have more than 6 charges of Elemental Storm your spells cost 20% more mana. 1 point passive.
b) When you stop channeling spells you get a burst of manaregen equal to 1.5% per point of mana spent on channeling for three seconds. 10 points passive.
I hope these passives will help Sorcerer to be a mana powerhouse like it really deserves. Feedback is welcome!