I agree , Thunderstorm is the most useless skill a sorc has. Well actually, Sorcs have a few useless skills, Telekenisis comes to mind ( unless you use energy shield)
Only use Energy Shield if you are going to put 16 hard points into Tele, otherwise you are wasting your time, you will be loosing more total HP + Mana, than you would just be loosing HP.
Since 1 point in either Vitality or Energy will have the same effect, 2 points of either life, or mana then there is no cost benefit in having an energy shield with less than 16 points in Tele.
These have to be real hard points too, having 10 points in Tele and +6 skills to get 16 total doesnt work. Synergies only benefit from real points placed in the skill.
If you use energy shield, be prepared to use at least 20 skill points in it, 16 in Telekenesis, and 6 In energy shield for a 45% absorb rate.
Lets compare some numbers with a level 10 Energy Shield 59% Absorb
(assuming 6 hard points and +4 skills)
Monster does Points in Tele Damage Damage with
This amount of if you had energy shield
Damage no ES Mana + Life
100 1 100 114 + 41 =155
100 5 100 100 + 41 = 141
100 15 100 63 + 41 = 104
100 16 100 59 + 41 = 100
100 17 100 55 + 41 = 96
100 20 100 44 + 41 = 89
If you only have one point in telekenesis, then you are actually way worse off than if you didnt even have energy shield, as you will loose 41 Hit points ( as opposed to 100 , however 114 Mana V 0 Mana.. there for you are 55 points worse off, when both points cost the same, this is obviously a poor choice.
Energy shield also requires a good warmth, 20 is good... this means to max energy shield you need to sink 60 points into it...
Its just not a viable option.