The problem arises when one side uses a term, such as "power" in a way where the meaning is not clear. Technically power is just energy per second. People rarely mean that. If one refuses to define one's terms then it is impossible to communicate accurately. And people often abuse terminology and refuse to define it as part of a tactic since they have no real evidence.
When a person uses a term he has to be able to define it when someone asks.
Defining is important, but also acknowledging, people use different definitions and understanding of terms. Take for example, sorcery/magic/witches/sorcerers. In the past, it had negative connotation and was seen as getting power from diabolic forces. Now in the west, it's presented more of a neutral thing, it can be good magic or bad magic. White magic or dark magic, or some people say no such thing as white or dark magic, there is just magic, you can have good intention or bad intention.
The way magic is defined now in the west by neopaganism for example, all actions can be seen as magical in nature in a more broad definition, so then in this usage, magic loses it's negative perception and more people are intrigued by it.
Then there is the tricks magic thing, which has nothing to do with spiritual power at all, but just is slight of hand.
The term on "god' is actually a semantic battle. Arabs that argued with Mohammad (s) about it, all acknowledge Creator as higher, more absolute in greatness, but they weren't willing to let go of the usage of the term god for their gods. In Islam, is highly important to reserve a word of love and reverence for God that is unique to him, and the highest form of love and exalting is Worship.
If not the Creator, what will we love the most and exalt the most? The semantic purification of these terms is essential, because we naturally value wealth, culture, people, as much God or more then God, so we have to strip the title of gods from Prophets, Messengers, and Angels, for a reason.
The word "leader" is something everyone takes lightly, but how did Quran discuss it? Authority, leadership, proof, religion, these are all debated terms.
I agree it's important to define terms, but who get's the authority to do that? Language itself changes time to time and translations are complicated for a reason.