There's a quite a bit more human energy going into war and destruction right now than into "peacefully collaborating among mankind to discover and explore planets."
If they were observing us today, they'd still see plenty of war and destruction.
It just so happens that a fraction of the worlds population lives under "peaceful" conditions. That's not universally true.
Source: I'm both an Arab and a Muslim.
We don't call the Spanish conquest of the Americas a Christian one even though they were Christians who ultimately converted everybody to Christianity.
What irritates me greatly is when historians refer to the Muslim scientists of the Islamic Golden Age as "Arabs", when most of them were not Arabs at all. It's such a simpleminded and sweeping generalisation that clearly shows the thoroughness of the so-called orientalists.
I agree with you about the second point. I guess it's due to the fact that they wrote in Arabic and many of the people they actually belonged to no longer exist (for example al-Khwārizm was from a Persian family but born in what is today Uzbekistan - I actually visited his hometown :)
To me it's strange to ascribe such areas of study to the religion. What does Islam really have to do with optics besides Ibn Al-Haytham being a Muslim? No one ever ascribes enlightenment science as 'Christian science'.
Hence the 'weaker' nation feels deprived of its history when its proudest moments are appropriated away.
Is there something uncivilized about the Arab conquest of Byzantine lands? Had the Kepler 452-b-ians been observing Earthians but a few hundred years prior, they'd have seen the Romans doing much the same to expand their own empire. And the Arabs did quite a good job to not only preserve the Roman intellectual and scientific state of the art, but to contribute their own advancements of those fields.