Can anyone tell me what was the role of Alps and Alpine region in Swiss development of Switzerland?
The Alpine Mountains were HUGE in the development of Switzerland.
There is a reason that Switzerland contains French, German, and Italian speaking regions. These regions were the main area in each linguistic group that could successfully resist the feudal lords of what later became the "countries" of France, Germany, and Italy. The polyglot members of the so-called Confederation of Helvetia basically banded together for mutual protection from these lords, in their own common interest.
At a time when the stirrup gave a huge advantage to cavalry over infantry, thereby allowing rich, mounted, knights to terrorize and "enserf" poor peasants, the mountainous Alps gave the infantry of "Switzerland" the wherewithal to fight back against attempts to force them into serfdom (as was the case for the mountains of Greece and Rome before them).