As a beginner, I don’t want to stuff my brain with needless words such as ‘interwoven’ or ‘wool’ for example. But as I progress, I will. When I come across such words, should I put them in “known words” or “ignore” if I want to re-introduce them later? (btw, what happens to ‘ignore’ words, are they ignored forever, and can I see somewhere which words I’ve ‘ignored’?)
You should only ignore things that are not words or are words in different languages. For example, in some Russian articles by Evgeny you can see some English and German text. Click ignore on these words.
You should add Lingqs for every word that you don’t know because as you progress these words will come up again and you will save yourself work later on. I don’t think it’s a good idea to add a word as known that you don’t actually know because you will inflate your known words count.
As for words such as “wool” or “sock”, none of which I can remember in Russian now, just don’t spend too much time on them. You’re right that some words are more important than others and you might as well not waste your time trying to memorize these words. But I’d add them anyway as lingqs.