#1 (rapid evolution) is not a sign of language dying, it is a sign of language living. Only dead languages don't evolve.
#2 and #3 are true, not sure if they are a sign of death. As a (Danish) kid I found Norwegian (bokmål) far easier to read than Danish.
#4: I don't believe the ads are significant, and certainly not English street signs in areas a tourist may visit.
However, the last example is what Danish linguists consider the greatest threat to the language: Domain loss. Danish is really to small a language for specialized domains. When I write about my work, I use English, as the majority of people who might potentially be interested are from outside Denmark, and those Danes that might be interested can all read English. A generation ago similar texts would likely be in Danish, but a generation ago there was far less international collaboration.
[ Domain loss in Denmark is nothing new, Latin, French and German have all been dominating various domains earlier. The German dominance was far greater than English today, before the rise of nationalism Danish was merely a peasant language, and even for the peasants German words replaced Danish to a large degree. ]
From my (limited) experience, it feels like small European languages are particularly susceptible to domain loss from English. Since they all share a common alphabet and the phonemes are "close enough", it's often trivial to grab a word or phrase from English when there isn't a proper native substitute. The technical fields are obviously going to go first, but other fields will follow as the world changes.
English is a highly predatory language. It absorbs foreign vocabulary extremely easily, and the grammar is remarkably flexible. If a language doesn't cover some conceptual territory, odds are that English will step in to fill the gap. I can easily envision a world where most people eventually speak some kind of English creole.
Oddly, the only major language (100 million+ speakers) I've seen that's resistant to English invasion is Chinese. The pictographic writing system, coupled with its monosyllabic tonal nature make it really hard for Chinese speakers to use unmodified foreign vocabulary. English has grabbed a number of Chinese words, but the transfer has been almost entirely one way.
I'm sure there's other languages that are incompatible with English, but they're in a distinct minority. I think the rest are going to experience at least some domain loss to English.
the only major language (100 million+ speakers) I've seen that's resistant to English invasion is Chinese.
This is not at all true of spoken Chinese. Having lived in east Asia for six years of my life, I can recall countless conversations I've overheard in Taiwan, Hong Kong, and China in which English words were intermixed into Chinese sentences by native speakers of Chinese speaking to other native speakers of Chinese. I've also heard a lot of use of straight-up English in "Chinese-language" broadcasting for local audiences.
After edit: I should point out too that most of the modern scientific vocabulary of Chinese is composed of compound words that are formed on the model of English or common European words for the same concepts. English ends up being a better launchpad for study of Chinese than I would have guessed when I began studying Chinese in 1975.
Domain loss doesn't mean importing single words. Importing new words, especially for new concepts, and adjusting them to the native grammar is just natural evolution of the language.
Domain loss mean that we switch fully to another language, including grammar. This is very close to be the case at the Danish universities, where almost all research is published in English, and more recently, most courses are taught exclusively in English in order to attract foreign students.
I'm intrigued by your comment that German dominance was far greater than English, for some reason I don't think that's true. Could you expand upon this?
No foreign language has had greater impact on Danish than Low German ... 16-17% of the Danish words are from Low German, 4-8% from Greek or Latin, 2-4% from French, and less than 1% from English. [ For comparison, around 2% of the English words are from Danish (from the viking era), according to Joseph M. Williams _Origins of the English Language_ ].
I have been told that German almost made it as the official language of the entire USA when the constitution was set up. The legend says it lost to English for a few votes, but that poll apparently didn't take place.
In any case: "On January 13, 1795, Congress considered a proposal, not to give German any official status, but merely to print the federal laws in German as well as English"
The United States has had a lot of German-speaking residents since colonial times, who became United States citizens when the country was founded, but there was never, ever a serious attempt to designate German the national language. Theodore Roosevelt campaigned for the presidency with German-language public speeches (and also French-language public speeches), and my two maternal grandparents, both born in the United States, were educated solely in the German language, but English has always been the main interlanguage among the various ethnic communities living on United States territory.
#2 and #3 are true, not sure if they are a sign of death. As a (Danish) kid I found Norwegian (bokmål) far easier to read than Danish.
#4: I don't believe the ads are significant, and certainly not English street signs in areas a tourist may visit.
However, the last example is what Danish linguists consider the greatest threat to the language: Domain loss. Danish is really to small a language for specialized domains. When I write about my work, I use English, as the majority of people who might potentially be interested are from outside Denmark, and those Danes that might be interested can all read English. A generation ago similar texts would likely be in Danish, but a generation ago there was far less international collaboration.
[ Domain loss in Denmark is nothing new, Latin, French and German have all been dominating various domains earlier. The German dominance was far greater than English today, before the rise of nationalism Danish was merely a peasant language, and even for the peasants German words replaced Danish to a large degree. ]