Can you give some specific examples? I would say that, unless you have some additional qualifications (European ancestors, EU spouse and similar), the majority of EU countries actually don't make it that easy. Of course, it depends on your definition of "relatively easy".
Yes, it's never a trivial process, so a lot of work is certainly being performed by that "relatively": I have extensive personal experience with the UK immigration process and know of the US equivalent through the experiences of former colleagues back home. France, for example, is five years to a passport/naturalization. Germany is three years of skilled work to indefinite leave to remain. The Netherlands is five years to indefinite leave to remain. None of those examples require European ancestors, EU spouse etc, but generally it's easier if you have a university degree and work in the various fields most readers of hacker news do.
Well, naturalisation in most EU countries would involve some other requirements: language knowledge (you'd have to pass an exam) + civic/constitutional exam or integration test + naturally, no criminal record, etc + some countries are quite restrictive on dual-citizenship (i.e. they don't allow it for foreigners, meaning that you would need to renounce your original citizenship).
Visas and residence permits are, of course, easier.
Ironically enough, Vilnius is now a very beautiful, safe and high quality of life city that is a better place to live than, probably, quite a lot of American cities..
When I was a kid, "starving children in Ethiopia" was a reason to eat your whole dinner. My formerly Swiss grandma once said "starving children in Europe" and I was very thrown for a moment.
Well, it is not really a new problem. Stopping-starting nuclear power plants is also slow and costly. Pumped-storage hydroelectricity and industrial batteries are good ways to solve it at the grid level. In addition to the possibility of some local solutions others have mentioned.
It was the case during the Soviet occupation and briefly during the transitional period, but otherwise - no, it wasn't. For example, in 1990, Latvia simply restored its 1922 constitution (still in effect today, although with some amendments) which enacted Latvian as the sole official language. This has also been the case with Lithuanian and Estonian constitutions, respectively.
You are counting from some early planning phases. Compare, for example, how long it took for the UK to build High Speed 1 line.
It's worth noting that the non-HS standard gauge (part of Rail Baltica I) between Poland and Lithuania (up to Šeštokai Intermodal Terminal) was completed back in 2015. The freight trains have been operating on this line all the time.
The work is very much ongoing in Lithuania: 114 km of railway is under construction, with tracks already laid in large parts of it. That is 43% of the initial phase (links to Poland and Latvia).
Let's keep in mind that it's not just standard gauge track. It's a high-speed rail project (200-250 km/h) and, for any country, it takes time to build such a huge infrastructure.
Baltic States can disconnect already in case of an emergency. The infrastructure is ready, several tests have been conducted. Lithuania wanted to disconnect already, but Estonia pushed for more conservative approach: they want more synchronous condensers to handle a higher number of possible simultaneous failures in the system. It's a technical debate whether that is necessary (Lithuanian operator thinks it isn't): the probability of such failure is already very small, but the Estonian operator wants to reduce it a bit further.
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