As somebody who only views Go from a distance, I see this list as a combination of „what‘s the big deal?“ and „please don‘t“.
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My experience developing in it always gave me the impression that the designers of the language looked at C and thought "all this is missing is garbage collection and then we'll have the perfect language".
I feel like a large amount of the feeling of productivity developers get from writing Go code originates from their sheer LOC output due to having to reproduce what other languages can do in just a few lines thanks to proper language & standard library features.
I think the end result is code which is quite easy to understand and maintain, because it is quite plain stuff with a clear control flow at the end of the day. Go code is the most pleasant code to debug of all the languages I've worked with, and there is not a close second.
Given that I spend much more time in the maintenance phase, it's a trade-off I'm quite happy to make.
(This is of course all my experience; very IMO)
Its premature if I don't know the answer to that question with my current information, which is a common scenario for me when I'm initially writing a new set of usecases.
If I get a 3rd copy of a thing, then its likely going to become an abstraction (and I'll probably have better understanding of the thing at the time to do that abstraction). If I don't get a 3rd copy of that thing, then its probably fine for the thing to be copied in 2 places, regardless of what the answer to my question is.