I was curious of the same question. Thus far everything they've been teaching has been current tense, as in currently is not eating. When you click on spiser it does however say it means both is not and does not, so i suppose it's the same either way, just a matter of context.
Yes, you're correct. Strictly speaking, there is no present continuous tense in Norwegian.
Mannen spiser ikke pasta, means both of these:
"The man does not eat pasta."
"The man is not eating pasta."
I assume that in normal speed spoken Norwegian, it must be very difficult indeed to distinguish "mannen" instead of "mann". Looks like sentence context is the major clue