Since we're all worried about Furaffinity's stability and people are talking about archiving options, a word of advice:
Don't get too aggressive with archiving just yet. Bandwidth is expensive, and if we're worried the site might be teetering on the edge in the next bit, getting too aggressive with automated downloads could be the thing that nudges it over the edge - or at least gets the tool you want to use banned. Go a little slower and a little more methodically for a bit.