sbf: It's [the question if mountains exist] the wrong question for a number of reasons
Firstly, I duly notice that since we are now talking about something you believe to be the case, you have switched back to universals: If mountains exist or not IS the wrong question; all other facts on the other hand are not really facts.
Secondly, i noticed you have not answered in what sence the question is "wrong". Is it morally wrong? is there something illogical about it? is it because inquiery if things exist or not (atoms, lions, mountains or causes for disease) is an enterprice that in your oppinion do not lead to results? Oh well, lets hear the reasons:
1) First of all it has no practical implications
this is not an argument, but simply stating something you might believe to be true but seem trivially false on experience: If for instance you are building a road, if there are mountains or not is of the utmost importance. if gods exist or not are a matter of life and death to billions of people and if you go to the doctor for a cancer screening I think you will certainly be interested in knowing if there is or is not antibodies in your blood.
2) Additionally words are simply sounds or signs that make sense in context by convention.
This is at best confused. Firstly the statement, if true, is not actually connected to the actual question "is the question: "does mountains exist or not" wrong". Secondly, and allmost implicitly despite the deflationary language, words are not "just" signs and sounds; its a classic case of a deepity.
3) A mountain does not know it is a mountain and if there were no humans to call it such no one else would either.
Okay let me get this straigt: It wrong for us to ask if mountains exist or not because mountains do not know they are mountains, and if there were no humans, nobody would either. QED. I love this display come only a few posts after you thought on Russel: "the blandest most derivative "philosopher" of the twentieth century".
4) Who is to say we could not conceive of geological formations differently so that there was no need for the word mountain?
If things were different, we might ask different things. It still does not explain whats wrong asking a certain question in the real world where things are as they are; again poor logic.
5) A mountain as such does not exist apart from as a concept used to tame the vast and unfathomable reality
Actually they do. I will quote Rorty, the same quote I believe you used earlier:
R.Rorty: one of the obvious truths about mountains is that they were here before we talked about them
So mountains exist, at least according to Rorty, but if someone ask me if mountains exist, that question is "wrong". Again you are very far from making it clear why I to should suppose that question was "wrong".