Of course some basic laws have been added since the birth of the web. You are not allowed to flood a site with requests and so on. But the principle that browsers and websites are separate entities still applies.

If you want full control over your users clients, create your own protocol and your own client. As long as you use open protocols on the web, you implicitly agree to the contracts of the www and have to live with the fact, that the user chooses his client.

By default, yes, but if you then explicitly override that with robots.txt or a TOS, those take precedent. (Again, I'm not talking legally here, just what's been the cultural custom for the past 20 years or so. In other words, if you ignore either and then get banned, I don't think many netizens would shed a tear for you.)

The court went with the side of the cable company, even if many commentates disagree. What effect a Swedish case can have on German law depend, but using European court case as guides is quite common in Swedish courts if there is no other prior cases. Same might apply for German courts.

It is part of the bigger problem, that courts do not understand every aspect of our complex society and have to listen to experts, which just defers to problem to the election of these experts. You do not want to give them the power either, because they are easier to lobby than justices.

I just hope, that a generation of justices and politician arises, that understands basic principles the web is built on. Like links, that give the web its name, and how they work, who can control them and so on.