What I consider a god is my choice.
Yes. Exactly. It is.
Which means that when you talk to someone else, who also have their own choice of what to consider God, and the two choices are different. Then you're talking about two different concepts, hence the misunderstanding. That's why sometimes atheists (who has decided that God is only defined as X) can't convince the theist (how has decided that God is not defined X, but rather Y) that his God doesn't exist, because they're talk different things. So the first step is... understand each other's definitions, if possible (which isn't always possible to do).
I suppose that if you believe in nothing beyond what I believe in but choose to use the label "God" for some of those things, then yes, our disagreement is nothing but semantics, sort of... though I'd have the same sort of "semantic" disagreement with someone who refers to the celebrity he stalks as his "girlfriend".
Sure. But I'm quite sure that if you start analyzing your own vocabulary and use of words in your daily routine, that you are using alternate words for the same things to carry alternate meanings. For instance, you might say you're "happy". Well, happy is only a subjective description of a mental state that you are in at a moment. It's just chemicals, signals, neurons firing and misfiring, and really nothing else. And someone else might even experience is somewhat different, because we're not the same and we don't know how it feels for another person. We can only study the signals. So the word happy, makes sense, but only on a subjective level. And it's a word that describe something that doesn't really exist. From now on, maybe no one should use words like happy, sad, angry, anxious, tired, and such, but replace them with the chemical imbalance descriptions. "I'm B12 deficient today." or "My endorphins are raging". Or "I feel heart palpitations and euphoric." But, of course, it needs to be expanded since there are more chemicals and states of the neural system that has to be accounted for.
... though there's also the issue of approach: from my perspective, it seems like a lot of "non-traditional" theisms are a matter of rejecting traditional theism while staying desperate to apply the label "God" to something without regard to whether it really fits. I think this approach is unreasonable.
That's your choice. What you find pleasing to your mind or not is your side of the coin. If things are to be fair, the choice, the values, the feelings, the whatever subjective thing we can think of apply to your side, then they have to be allowed on the other as well.
You think it's unreasonable. I think it's not. I actually think it's more reasonable, because not only as a pantheist can I fully embrace a proper and leveled understanding of atheism, I can also build a positive and constructive worldview out from that point. Atheism is not a religion or value system. It's not a worldview. Atheism is only the CLR button on the calculator. Atheism is the Reset on the computer. It's the eraser on the drawing board. But what then? After you have erased everything, don't you want to start over and now paint a picture with something move valuable? Atheism is only the step of starting over. Pantheism is one way of going forward (and probably not the only option, there are many ways of painting a painting).