Every downside to golems you mention can be either eliminated or mitigate with skill. Furthermore, all the problems you list are unique to Rath Castle Shadow Missions, which does not constitute a refutation of the "golems are broken" contention. Just because a skill is less broken in a certain area, does not mean it is not broken in other areas.
Things like cerberus make all kinds of problems trying to control a golem. fast sulfur spiders and explosions will break your concentration all the time too. mage and archer fomors also love to disrupt you. And every time you're disrupted, your golem unloads whatever skill you had loaded or partially loaded... forcing you to start completely over loading after switching back.
]As said before, golems are not really ideal in every situation. A melee player can rely on his/her skills in far more places (hs3 is really rare). Damage output is not the only factor, as any top-end melee player and/or any golem user can tell you. Damage is important to newbies trying to get a handle on things, but end-game is about far more than damage.
You talk like there is no skill curve for golem usage. Judicious use of barrier spikes? A good pet AI that can support your golem? Good positioning to avoid aggros? And when a high-rank golem loads WM, every mob in a normal dungeon room gets hit. And this is just solo play.
I'm also reminded of some arguments back in c1 about windmill. Even to this day, everyone says you should get windmill, even though it is clearly a melee skill, for every build. Be it range, mage, or melee (or alchemist even these days). I've often thought windmill should be nerfed, if it is so good that absolutely everyone should have it. But the reason it is not actually overpowered... is that anyone can have it. If you think golem is powerful... then rank it up yourself. Sticking to one skillset or another is a choice made by you, the player, not by the game. Skills are never going to be equall in power or usefulness. Get over it
WM is important because it's a reliable defensive skill in a pinch regardless of how much damage you actually do with it. As a main form of damage it's actually nowhere near broken, as it forces meleers to choose between damage output and survivability, and relying on it as a main skill has a skill curve as high as anything in Mabi (unless you don't mind dying a lot; WM reliance forces the player to play virtually mistake free). It's still the best overall skill in the game because it's so incredibly versatile and it's accessible to any skillset with any weapon, but as a primary means of attack, there are *lots* of things that trump it.
Golems actually negate the main downsides of WM, because the health expended in Golem WM is expendable - you WM a few times, your golem dies, you summon another.
And in any case, this is a non sequitur, since we are not discussing whether golems trump end-game melee in all cases - we are discussing the fact that a
level 350 player can dish out damage rivalling end-game melee. When you consider the time involved in getting to 350 versus getting to 3500, then the utter imbalance of the skill become s apparent.