The Introductory Paragraph.

• "'if not one of the most difficult skills in the game to rank' - opinion. It can be easy to some and hard to others."

All right I'll give you that. How about "is one of the most Combat Power sensitive skills in the game"?

• "'Rank 4 for humans, for example, requires a minimum of 3,550 kills' - This sentence is useless, one could just look down at the page for rank 4 training and add them up."

Just because all the data is there doesn't mean it can't be restated. Take Healing for example, the mana cost and healing amount are there, but why do we need the efficiency listed as well? Couldn't someone do the math on their own? Yes they could, however, it draws the reader's attention to a useful fact that may not at first be obvious just from looking at the numbers, or that may be easily overlooked. I'm pretty sure that windmill requires more kills to rank up than any other skill in the game, and that number provides context and a sense of scale for that fact.

• "'it is recommended that the anyone wishing to rank this skill do it early or else be prepared to purchase Combat Power lowering enchantments.' - Recommended, but not necessary. It's very possible to rank the skill with high CP and no CP modifiers."

It explicitly says "recommended". What's wrong with that? I'll remind you that as per wiki policy, the wiki's goal is "...to provide as much information as possible on all aspects of Mabinogi." I don't see why that fact would be excluded under that mission statement.