Is there a coterie of tech experts in this community who respond to technical questions?
About what? Just ask. Don't ask to ask, and don't expect people to self-evaluate their own expertise.
Do you always speak to people in a scoldy tone the first time you approach them?
This guy aside the question stands.
Ime, yes and no, usually there are couple areas each of us (those who answer questions) are very knowledgeable in some areas (sometimes more than a so called "tech expert"), but lack knowledge in other areas, but that's why its called a community, collective knowledge is generally greater than individual knowledge, and even "tech experts" generally don't know that much they just know where to find the answer, at least according to my friend who is a "tech expert"