Psiclones don't give any kind of stat bonus - I'm not sure this would even be possible right now, even with y-scripts.
What they do is serve as a really crappy stun rod with a panic effect. The panic hit is pretty strong if you have psionically gifted agent, but usually just once per turn and at melee range, so not terribly useful, even with the stun rider.
The best defence against ghosts is offense. Psi weapons tend to go through armour like a knife through butter, and poltergeists can be dangerous during missions where you can't wear any kind of strong armour. You might get a little bit of defence by wearing excessively thick armour - but even then, the effect is marginal (10%) to none (0%).
As to workshops, I generally remove the space limits myself, so my answer would be "as many as you can cram in there". With limits, I would guess perhaps 80-90% of full capacity, depending on what you're manufacturing most often. Do note that your workshop capacity is not limited to just workshops (hangars are the big extra contributor), so you might want to fill the two workshops to 100 and have a few hangars' worth of extra space. OTOH, I tend to play a very altered manufacturing game, so take all this with a big grain of salt.
