which one is better Wiz 3 - link 1 - thau 2 - ff2
or wiz 3 - link 2 - thau 1 - ff2 for general pve solo?
is it worth taking more than one linker circle since many mobs are getting immune to jp?
Linker 2 > Thauma 1 > FF 2
Yes.
RI 
or wiz 3 - link 2 -sorc 1- ff 2
why sorc? 2020202020202020
i have one more question about skill allocation. Would this be fine?
http://www.tosbase.com/tools/skill-simulator/build/tv4lu5tj4i/
Sorc’s kinda pointless, if you’re going link 2, go all the way or take Thaum 1 if you dont want Link 3.
To clarify:
Sorceror is pointless if you take only ONE rank. Since you lack the control skills necessary to position your summon and also because the scaling is bad if you take only 1 rank. (lvl 5 summoning gives 0.8x INT of damage to your summon vs lvl 10 1.3x int)
Edit: Your build seems ok though you should check out the FF thread on the forums, I read somewhere that Bloodbath makes up most of your damage or something.