All things are relative. There was no German city without at least something of military or industrial importance.
Exactly. In fact, the USAAF underlined that with their targetting policy later in the war, which defined military targets to include any city with a railway line, road or rail bridge, etc, then said that any town big enough to show up on radar would have such things and may be assumed to be a military target.
It's just stating the obvious, cities were production centres, and in war a large part of production goes to the military.
It is generally accepted that Lübeck was a purely retaliation raid.
I don't think so. It's generally accepted that Lubeck was chosen ahead of other cities because it was an easy target that could be expected to suffer a lot of damage. As already noted, like any other city it had it's share of industry. Why not hit the easily damaged targets first?
As I said, the ordered aiming point was the center of the Altstadt.
I'll take your word for it, it wouldn't be unusual. The RAF developed their policy of targeting the centre of the city after British experience with German raids in 1940 and 1941, in fact the first RAF area raid was authorised following the Luftwaffe attack on Coventry, and took it's example from that attack.
What the British found is that damage to the infrastructure of the town (water, gas, electricity, housing, transport etc) was more damaging than damage to individual factories. I could expand on that if you like, but it really belongs in a seperate thread.
Am I missing something?? It's the first time I heard the Gloster as being the first operational jet...
Are all the sites wrong?
Mostly, yes. Note there is dispute over the true definition of operational, and the argument is really a bit silly, as both were introduced at almost the same time. It's more a question of semantics than any real historical significance.