High five! That’s my class build. If you want to have more offensive skill then go for pyro1 after wiz1. If you want to have cc skill go for wiz2. My skill on wiz2 goes like this, energy bolt 10, sleep 10, reflect shield 9 then earthquake 1. Energy bolt is useful especially if your next class is psychokino. You can enhance e.bolt till 100. Last icbt2, i enhanced mine till 60+ and its still useful till 150+ at demon prison.
I put earthquake to lvl 1 because the damge svck as you reached higher level maps. However, its a good cc for pvp even if its lvl 1. Also, earthquake 10 or 5 is only strong if youre level 100 below. Also, theres a wand at level 45 that gives you +3 level on earthquake. 
pretty useful.
As for psychokino skills, i believe youre already aware of every skill. Both necro and sorc are good, but im going to use sorc2 and have a rank 7 class or necro. Cant decide atm. Hehe.
Edit: im going to answer some of your questions later. Gonna be late for work. Lel.
Edit: AM BACK.
Ok, i’ll answer question number 4 now. Actually you can have both. Summon servant level 3 will give you sp regen, mdef and aoe addition. Not sure on the second, coz i already forgot but you will surely have sp regen and additional aoe at summon servant level 3. If you max servant, you’ll get stamina regen and additional damage for dark attack. You can put level 2 summon salamion since the duration of salamion and cooldown of the skill is the same, so just re summon him. 
@Question number 5:
Meh, i dont have knowledge on necro lel.
Question 6.
Hmm. I dunno about the other summoner, but i put average SPR and CON on my character and make sure that INT stat is higher than those 2. They say that if you put high SPR on your sorcerer is bad due to the mana% drain. To be honest, its not really that hard to maintain your SP. I mean, i use psychic pressure while my summon is out (dungeon or grinding). It’s all about the timing. Alchemist pots has a low cooldown so if you ever hit 500+ below sp, just use it while PP is cooling down. Then Alche mana pots again till you reach 80%~90% of your SP.
Also, when in dungeon, i always use some of my skills while summon is out so that i can be helpful. Whenever my SP reached 60~70% below, i use alche sp pots and use it again after its cooldown to maintain my mana. My point is, even if you have higher or lower SPR, alche mana pots will always save you. Huehue.
