Kerrick said:
Composite Materials: Very interesting, and it makes sense - if I've got one or more oversized limbs, wearing armor would be really difficult. Robes, however, would be less so, since they're generally made to accommodate larger body mass. I'm not sure about being able to enchant the golem parts like armor - that's what the natural armor bonus is for, and they get light fort on top of it. Yoinkworthy
Light Fortifcation: Definitely. I'm borrowing this one too.

Wish that I could take credit, but to be honest, I myself yoinked those elements from the warforged race detailed in MM3. That's also where the living construct stuff comes from; it's a new type they came up with for Eberron. I figured that the type fit a half-golem a lot better than a straight construct or humanoid would.
Berserk: I think only clay and flesh half-golems should have this (the prohibitive costs of stone and iron limbs balances this out). I'd rewrite it so... Simple, elegant, and it gives a (small) chance for a living being to keep itself under control. I don't totally agree with the barbarian rage stacking with this one - that's a huge jump - so I ditched it.
Ah, see, but why would a player want to end it? That was what I was struggling with when I started this rewrite. Generally, players look at the rage ability as a plus, thanks to the barbarian. Why would they want to end something that's giving them extra Strength and Con? So I tried to make it a flaw by making the half-golem's actions random while under the influence of the ability. It didn't really work out. So I switched to the current ability, which gives them the equivalent of a barbarian rage once per day. The stacking thing is something I kept over from MM2. I kept it in as an extra perk.
I'll admit that giving Berserk to all half-golems was a result of a personal preference of mine. Whenever I think of golems, I think of the original myth - a thing created by a holy man for protection goes insane and out of control. WOTC tends to use golems as the fantasy equivalent of robots, but I think that element of violent madness from the story makes them a lot more interesting.
Also, I might explain the Berserk quality as being a result of combining living tissue with golem parts; you never know what's gonig to happen...
Giving flesh half-golems a breath weapon is a bit much. They're the weakest of the four, and the flesh golem doesn't get this, so it makes little sense.
I had to give flesh half-golems something, or they'd have a different CR and LA from all the others. Which might be what you're looking for; me, I'm too lazy.

To make this template, I essentially combined a warforged with the half-dragon template, with a bit of a half-fiend mixed in (both of which seem pretty standard as templates go). That's where I got some of the attacks from that didn't fit the original; I made the iron half-golem's breath attack acid simply because that's what the half-dragon gets, and I get the feeling that a lot of work went into figuring out those special attacks.
In any case - thank you very much for your time, Kerrick. You've been a big help. If that's all, everyone, I'm going to call this template a wrap. Thanks again, everyone who commented.