It's always a good time when the topic of upgrading old doom or ToT artifacts comes back into discussion. It's nice to see that you have a lot of ideas after a less active period. I'm happy to start a little mess here
Rune Beetle Carapace - Just a slight upgrade over RBC from VvV, which isn't much better than regular rbc anyway. Just some more resistances is all we got there. If you want to make it usefull (i doubt its ever gonna be but lets try) we have to add some more mods since resists are no longer difficult to assemble. Maybe something like 10int bonus and one more mana regen?
Swords of prosperity will only give you an advantage of 20 luck and 1fc (not if you use a shield with donation drive) if you use 190 luck shield and weapon. The price for 20 luck are shield and weapon bonuses like mr lmc resist and whatever else. Not a good deal especially if you wear that shield and mentioned before. They may be some cheap temporary solution but I don't see it in the meta. What would I add? definitely some mana regeneration and lmc.
And finally - Kasa. The vast majority of PvE characters who need sdi currently use The Scholar's Halo, which I personally find much more useful. Currently, it is a replacement of 15lmc, 2mr 1fc and 10lmc with only 5sdi. I don't know if Kasa is intended to replace Halo, but even if not, it certainly won't be very popular in this version.