Well, too many words to answer.
1. Except “nationalistic Greeks”
There's one of 'em now!
there are hundreds of Anglo-Saxon scholars that say the same things.
Doesn't make 'em right; All Western Europe is drawn into the Graecocentrism from which it (not entirely accurately) claims its descent. If every one is wrong, everyone is wrong. Truth is not democratic.
I am not the nationalist type,
I gotta tell you; no questioning of the glowing ancient Greek reputation ever seems to pass you without challenge; I think you are a bit nationalistic.
but I have seen lot of ancient greek warriors in original artwork holding kopis. I have not seen any Caucasian.
I think I have; definitely in the steppes countries, and I'm pretty sure they've excavated the swords "up" there, too.
I believe that this sword is coming from an older form, most possible from Egyptian khepesh.
The resemblance is rather tenuous......and did the kopsh (so rebellious, I am!) come to Egypt with the (Northern Steppes) Hyksos? Still seeing if anyone will A/ defend/explain that concept, or B/ explain why these are thought to be closely related forms. Are you familiar with the Egypto-Palestinian broadaxe? You're really missing an important element if you're not. You (Yannis) are saying the copis came from Egypt? Do you hear Kamil saying the kopsh came from up north? (AFAIK it actually came at the same time as an invasion? which is hardly hard-and fast proof, though encountering relatively long swords could have inspired the Afrasians to turn their fighting axe into one.....)
Through emporium and colonies it was spread in all “known” world, before Alexander, from Iberia (Spain) to Colchis (Caucasus).
2. Of course exchange of technology (or ideas) is not one way, but Greeks pushed the wagon little further, like Democracy (Athens),
Democracy may be the natural human government. It is fairly common, but no one in Helenic (etc.) Greece practiced real democracy; they were a bunch of slave-holding elitists. They routinely claimed the profit from their slaves; what makes you think they wouldn't claim credit for their ideas etc? Modern Republican "democracy" coming out of the United States of America seems to have features derived as much or more from Iroquois government, BTW. And people are often taking credit for (for instance) my ideas, and those of other social outcasts who do so much of what serious thinking gets done (normal people go along, you see; it's contrary to thinking to accept the concepts that are handed to you, so by definition......)
Philosophy (Plato, Socrates, Aristotle), Geometry (Pythagoras), Physics (Democritus), Medicine (Hippocrates) etc. As far as I know the schools around the globe still inform their students about it.
Again, that does nothing to make it right or true, nothing to address the achievements OR lacks of any other culture, and does NOTHING to credit any of this to those particular individuals, and a study of history in general should show you that art, philosophy, etc. do not occur in a vacuum, but in a cultural context, which in works that "stand the test of time" is thereby indicated to be more cultural than personal, even where evidence of parrallel development doesn't exist, though it often does. For example, there was a whole school painting like Heironymous Bosch (sp?), but in US he's the only one you ever hear of or see his work. He was not the first, either. Pasteur learned vaccination from Africans. Many people were working on automobiles and airplanes contemporary with the famed ones who get credit, and who there is actually evidence (for both machines) "cheated" from ultimately "less successful" artisans/inventors. Much the same for electricity; a few quick top of the head examples of a very typical human behaviour, and I'm completely unconvinced that WHOEVER was leading the Macedonian army at the time would have done much different; it was bound to be an arrogant monomaniac, as A/ that's kings for ya, and (more importantly) B/ despite (not unusual) protests, grumblings, and troubles with the soldiers who actually did the deeds, that's what the Macedonian people were in the mood for. (the hated ruler is also largely a myth, though in these days the government armies can be so technologically superiour to the people to render it a real possibility. Take Hitler; the Germans loved Hitler.....) It is particularly in invention that the "Great men" theory is most obviously heavily flawed to say the very least, but IMHO this pertains as equally to politics, religion, etc. Often "great men" with some humility have creditted is as such (notably Thomas Jefferson, for instance). The farther back you go the less you'll find the tenuous and typically deliberately concealed/destroyed sort of evidence that shows this; that doesn't mean it didn't happen.
As far as is really accurate to go is that we don't have good records concerning the more northern peoples' philosophy, etc, largely as they appear to have been illiterate. In modern times, the distortive effect of Eurocentrism on perceptions of other cultures has been exposed as rampant and blatantly insulting, sometimes going so far as to deliberately destroy the antiquities of conquered peoples (notably in Africa and Mexico), often ostensibly out of religious outrage, but the created absense then is used to point to "primitivism", justifying conquest and rulership in some eyes.
3. Alexander was on the tide of Macedonians and the demand of all Greeks for revenge against Persians. But if it was not him, greek army would not reach India. A lot of times he had stand against his soldiers will to return home. He was clever enough to try new strategies, fighting against bigger armies.
This may be true, but as I say; as with pretty much all the "great men" stuff it's a cultural idea/interpretive paradigm of near religious standing in the "Western" mind; there's no real evidence for it; it wasn't neccessarily just his will, but that of the home country.
4. Talking about weapons, the Greeks, like any successful army, had studied a lot their weapons and developed new kinds of them for new strategies. For example, Spartans with sort swords and big shields developed the tight formation where each soldier was covering a partner. The Theban general Epaminondas 'invented' new battlefield tactics by concentrating his assault on one selected point of the enemy line.
A/ I think this is a more universal tactic than that, and, again, there is, and CAN BE, no evidence that this particular individual arrived at the idea on his own, any more than there's any that Shaka Zulu actually invented the long-bladed iklwa (whose name, BTW, contrary to silly legend, seems to be the same Bantu word as the Kuba ikula.....)