I have always asserted that the claim that the Rings of Power all provide invisibility is incorrect, and unsupported in the canon. While Tolkein may have had some ideas on the concept later, it would have required re-working the canon extensively. Certainly, there is zero evidence that the elf rings make their wearers invisible in the canon.
Thus, there would be no good reason that the dwarf rings did the same. And given that Thrain would have been difficult to catch by the minions of the Necromancer had his ring made him invisible), I think we can reasonably conclude that the Rings of Power do not all have that ability.
Open question on the Nine, though. Personally, I think no.
That final line, to me, cleary implies that the non-dwarven rings granted invisibility (or that they all granted invisibility, but dwarves themselves couldn’t turn invisible).
That quote is from JRRT’s draft of LOTR, and shouldn’t be taken as canon. It’s just interesting in showing how JRRT’s ideas had changed over time about the rings.
Well, yes, but there’s no canon answer as to whether the other rings can grant invisibility. I think that non-canon drafts should be accepted so long as they don’t conflict with more authoritative sources, which this doesn’t.
Crusades and Holy Wars are scary. Theological debates are entertainment, particularly those in which all parties realize that their theology is pure fiction.