Interesting read, however I would like to point out some problems:
1.)
ThermD @ level 8 won't really help you out that much. I tested ThermD using my Psi Sniper and obtained the following:

Effective meta skill = 125
ThermD = 175% Health damage (50% heat/50% Mech)
hits Tchort for 689 damage (405 Heat 284 Mech)
Tchort evades 130 damage (65 Heat 65 Mech)
Tchort resists 931 damage (405 Heat 526 Mechanical)
Raw Damage:
Total = 689 + 130 + 931 = 1750
Heat = 405 + 65 + 405 = 875
Mech = 284 + 65 + 526 = 875
So some simple math will conclude Tchort will:
Evades = (130/1750)*100% = 7.43% damage
Heat resist = 405:405 = 50%
Mech resist = 284:526 = ~65%
At 3 WIL level 8 you are only going to have 44 effective Meta skill, meaning ThermD will do 94% Health damage, so with tentacle you will get 940 raw damage, or (217 Heat + 152 Mech) 369 damage after resists + evasion.
Honestly I just don't see how you can do enough damage as a 3 WIL level 8 Psi. Your Neural Overload, even when crit, does very little damage (10-11 base).
*see
http://www.underrail.com/wiki/index.php?title=Neural_Overload2.)
Muzzled vs. compensated.
Muzzled will always wins out due to the fact the two extra bullets can crit. However this brings us to the next point which is ...
3.)
Focus stim does not help you in mushroom forest as hostiles there are immune to crit.
Remember even if you blow up all four mutagen tanks Tchort will still regen health (at a slower rate). With your damage output so low per turn I just don't see how a level 8 psi can win. I'm also doubtful a level 9 AR can win due to your low effective gun skill and Tchort's relatively high evasion.