You would be surprised at the dura loss of cylinders. It is astonishing considering how little they are used.
And whoever complains about the repair cost of Caliburn. That is your choice.
I'm not surprised at all. I run around spamming Wind Blast, Golems, Water Cannon, melee, and everything with a Cylinder when I'm bored. It appears to have the same durability loss rate as any other weapon, and considering Golems are summoned much less than any other weapon is used, it follows that the dur usage is also extremely low.
(Summoning a Golem uses about 5x as much dur as a regular attack. So unless you only get 4 attacks out of your golem, I doubt your repair rates are close to weapon status.)
And I think Caliburn is well worth the repair rates. The point was that a melee character can't even hope to be near a golem without it, and that it costs a lot.
The summon golem skill doesn't need any severe nerfs. The reduction in size already happened, and any limitations made to snow golems are fine be they already in place or coming. Neither will impact the main purpose of the skill as I described: a way for a new player to get a step-up into being able to participate in medium-average content.
The size "reduction" was overshadowed by the new skill that enlarges it. It's not really a nerf in the sense that it's potential was just drastically increased, both in size and in strength.
You're saying that newbie chars should be able to participate with end-game chars, but this is already doable with a single Intermediate Magic, or even just Windmill and a good head. Raw damage is good, but good teamwork is better.
Either way you look at it, even if it is intended as a facet to more easily jump into harder things, that doesn't explain why it's both massive and powerful. One or the other would be good, preferably the latter.