It's worded like that in case we want to add more sacrifice tiers above the Ultimate Sacrifice tier. There's no immediate plans for that, but to avoid having a lot of carefully worded objective strings that then need to be monitored and updated if certain situations change, we felt it best to be general in places like that.
You can also get 5 star hearts/idols from the Precious Soul too, and it would be unusual to get a 5 star character out of the sliver soul art we use for Common Souls. We felt the "middle" tier soul art that's the bigger sphere was the best bet with that in mind.
Many of the different talismans we've debuted for a limited time (Strike, Vampiric, Guard, etc) will return as farmable items in the Brave New World, but may also return in a limited fashion in other manners (like how Immunity Talismans were a 1 day deal last week in the PVP store).
As far as I know, all reported instances of hard or madness quests not counting for missions were fixed (which is bullet points 2-4 under Challenges Fixes in the update thread). While most people reported that many missions would not work except on normal, we found that most of the missions involving specific cosmos quests were set up correctly and just those 3 were not. If there are other instances of Madness version of quests not working, do let us know and we can investigate.