I can't hear "n" in "nyckeln", it's looks like "nyckel" .. is it correct?
I can hear it. Maybe an audio bug that has been fixed
I do not hear an "h" in har + is this the voice or the right way to speak
I can hear it, but it's admittedly faint. Swedes do often talk like this - with just a trace of the "h". But some pronounce it more clearly as well, so it's not a rule either way, just dialectal differences.