I'm less concerned with d100+50 (which I presume is World-Splitter) than with the questions of how artifacts relate to the game.
0) I wouldn't mind if there were a heroes section in here also, although it might be more appropriate to add it to a Worshippers book.
1) Are there 'natural' artifacts? (Items of historical significance that acquire properties linked to their legends?)
2) What happens to an 'eternal' artifact when the deity powering it no longer exists?
3) Can you bang two artifacts together for eternity, or will one of them eventually break?
4) If I hurl an artifact spear at the deity that powered it, can they cancel the effects before it strikes them? Unless the artifact is Eternal, seems like they would be. Side note: Do they have to disempower the artifact permanently, or can they hit some manner of 'off switch'?
5) Is there some way of packaging Belief (shen coins from Zelazny's Lord Demon)? What about 'use once' miracles, or artifacts that have a certain effect only until the mortal does something (the bag of winds from Greek mythology)?
6) The mythology of the selkie/human transformation indicates that modifying things is far easier than making them outright. If my followers find a lost sword, but need food, is there some discount for using the sword as raw materials for making a holy plowshare?
In other words, I'm more interested in the mechanics of artifacts than in statting out every one mentioned in the other books.