Indeed. Older books are available as dead-tree editions, as well.
Yes but remember Maxims 37 and 46 when doing a full archive binge.
It depends, from the core game there’s only three specific decks I can think of that could particularly do with improving the artwork,
and some other cards here and there (Tempest, Tachyon and Ra… Basically cards which rely on elemental type effects) although it would be nice to see more polish on it overall.
Which overall isn’t that many cards so could easily get away without needing it as such. However, that artwork does really impact how good those decks look and I would love improved art for various reasons for each - Tachyon for probably being the worst culprit and in need of it, Tempest for being one of my favourite characters and Ra for being a good beginner character so often will be some of the first artwork someone being introduced to the game will see.