Yes, we are only talking about the definition of a word. We are not talking about the more relevant break downs of what constitutes existence - yet.
If it is merely about defining a word, I do not see any problems at all. For me, you can define existence as that which comes which cows produce in their udders, as long as I am informed about the way you use this word when you talk to me.
What I was trying to point out is that our conclusions depend on the way we define words. If you define existence as something that excludes the mere objects of thoughts, the result will be gods do not exist, if you propose a definition that will include those objects, the resulting statement will be gods exist. Thus, the definition you (or anyone) proposes is designed to enable the desired break-downs (which makes them mere semantics, basically).
I found nowhere in your common usage, any sign of intent different than the proposed definiton. Each time you used the word "exist" or "existence", you were refering to something that has affect on something else.
No, in many cases I was not sure whether the assumed cause existed. As far as I am concerned I merely observe phenomena, and what I can observe I consider existing, for practical purposes. I have no idea whether they are affected by something and even less what it is that they are affected by.
Does love exist? Is it that which affects things, or is it the very affect we perceive itself?
I personally am fine with and if feeling loved. The question whether love exists does not really interest me.
How so? What else is required?
If visiting a friend I may ask in advance whether a guitar exists in his house. Philosophically, I do not believe that guitars exist other than as our concepts.
I don't see how you would have to change anything that you seem to do currently. Those who need to change would be those similar to the prior post who confuse the idea of a thing with the things existence and do so very readily such as to bring argument and cloud issues.
I personally wouldn´t be so quick to call this clouding the issue, anymore than I would regard any other definition as clouding the issue. What you are describing here is exactly what everybody else does, too, when defining words: Preparing the desired resulting distinctions.
He use of words is what is important in that bad usage results in confusion and further clouding issues.
Well, in your very first sentence above you were telling me that all this is merely the attempt of defining a word, i.e. a merely semantic question.

Now you are warning me of the significance of a definition for the result, and that is exactly what I am trying to point out.
It is important to acknowledge that thoughts do indeed have existence and therefore affect. If you were to leave that idea out, then you would begin to find people who argue that the thought of something brings effect and thus existence is created by thought (non-existence).
I am completely confused as to what you are trying to say here. Would you care to reword this paragraph for me?
There is a form of "magic" trickery that causes something to come into existence as a real thing simply because of the thoughts and what they affect.
I don´t know what you mean when saying real thing here. I do not understand the distinction between existence and real existence. The latter seems to be a tautology.
Those who are familiar with this type of thing tend to argue that the thought of the thing, being its cause, is the same as the object itself.
If I were to object to this notion, I would try to come up with good arguments against it, instead of merely trying to define this possibility out of existence by proposing a definition of existence that suits my purpose (magic trickery).
Thus it is important to begin by clarifying that any existence is quantified, not by what it will bring later, but by what affect it has at the moment being discussed.
I personally am not convinced that this is important.
Are you saying here that if you cannot perceive it, then it doesn't exist?
No, I didn´t mean to say anything to that effect. At best, your above paraphrasing would be an invalid reverse conclusion of what I meant to say.
For practical purpose I consider that which I can perceive as existing. In everyday life (and in reference to that which we call the physical realm), this definition seems to do. If I see a guitar hanging on my wall, another person looking there will see this thing, too. If she is blind she can feel it. There doesn´t seem to be much disagreement about the existence of something, at least none that requires, justifies or necessitates complicated philosophical considerations.
Enter concepts. Other people may conceptualize differently than me. Being a musician I may think of this perceived thing as a bass, while for a layman the concept guitar is entirely sufficient. A third person may think of it as a piece of wood for fueling the oven.
Yet, disagreement as to whether there hangs something on the wall are not to be expected. Further attempts of describing its properties are likely to give everybody involved the relieving idea that her perception works sufficiently similar to those of the other persons involved.
There are different degrees of abstraction. Whilst guitar is such a familiar concept that we are (mistakenly) are tempted to consider it something concretely existing, a concept like wind is already signifying a complex process other than something that statically exists.
For example we will run into problems determining what about this complex process must be called an affect or is rather to be considered a cause. Wind exists is a problematic statement, since we are already talking about an advanced conceptualization, a thought, if you will.
On the philosophical level we end up in mere abstractions. When talking about love, freewill, evil we are talking about abstract concepts. Do these things exist?
Actually, I don´t care much. Being abstract concepts, they are brought to me by my brain activity. I´m fine with everyone who wants to call them existing, I´m also fine with everyone who refuses to call them existing.
I personally experience myself to have those thoughts and concepts, and that´s all.
Returning to your question: I consider those things that are brought to me neither by perception nor my brain activity as irrelevant for me.
If someone claims to have personal conversations with god, and I don´t have such, these conversations are not relevant for me (the claim of the person may, though). Now, if I ask this person to invite me to join those conversations, and he comes up with funny excuses as to why that is not possible, I am losing interest. I will consider this entire thing irrelevant for me. Whether this god exists is merely a semantical issue, for me. He perceives it, I don´t. Fine. I will go with my perception.
That would mean that atoms, electric fields, the dark side of the moon and such don't exist because you can not perceive them. You must deduce their existence from the affects they have. Deduction is different than perception.
Deducing something from an affect is the textbook example for conceptualization. These things are mere concepts, thoughts, and I suspect you will have a hard time to demonstrate that they have an existence beyond merely being thoughts. They are useful thoughts, though, and they have proven to be appropriate explanations for our purposes. That´s why I find those explanations acceptable. The question whether these things exist is not really much of a concern, for me.
They reply, "He can't be seen, he just IS." I am proposing that they then explain what affects define the thing they are calling "the devil" else it is to be concluded that such a thing is merely a thought and no more.
I suspect that they will answer with evil or sin or unclean thoughts or something to that effect.
I propose that first a discussion of what constitutes existence be presented.
Well, I have tried to outline where I see the essential problems coming with this approach.
For the purpose of demonstrating my point I will propose the above mentioned definition: That which cows produce in their utters.

Anyways, I sincerely hope this thread will get you (and us) somewhere, nonetheless.
Finally, another thought I suggest to take into consideration: We do know that the feelings of something to exist can affect us in the same way as this thing being demonstrably there. I feel that this poses a major problem for your approach. If we assume that feeling a god to exist would affect a person in the same way as a god existing, I would a. have no idea how to conclude existence from affect, and b. I am even inclined to consider the difference irrelevant.