“Don't try the paranormal until you know what's normal.” - Granny Weatherwax
for example: i take celts. i advance on any row.
Do i make a pseudo culture action (take 1 culture card, move my culture track disk forward)?
if not, what's exactly the use of doing this?
Yes, as you said, it's like taking a culture pseudo-action: you also move your culture disk and take 1 culture card.