Shouldn't golems be immune to mental attacks? At least resistant?
No. If it has a mind, then it should be hurt by mental attacks. Since Golems have minds, then they should be hurt like every other sentient being.
I thought an energy golem was a machine.
What about Flint! He showed emotion througout the entire game!
Artificial intelligence can be considered a mind.
Though maybe the could have a physical resistance?
The way I see it, a sword can hit a golem and make damage, much in the same way a sword can hit a swordsman mechanic with an armour and make damage.
About the mind blast affecting golems, I recall discussing that in the old forums. One of the possible explanations is that mind blast provokes electric currents in the brain of the attacked that affects the connections between neurons (think that it's a short circuit in a brain). If we assume that the golems have a mind controlled by some electric device (or electronic, who knows what the mechanics are capable of), then the mind blast may affect equally the golems.
The way Barzul describes the mind blast in his story The Reign of Nelis the Merciless (http://sinisterdesign.net/forum/index.php?topic=66.0) happens to be much in line with my ideas.
A mind blast is to overload a brain with information. Many viruses damage computers by overloading a them with spam.
Yep. The flow of information in the brain is associated to electric currents between neurons.