BlockVader

That's just how a square trap (the same shape as the 3 traps before it) looks when blacked out. It's the pitfall trap. It's quite rare.

A chance to warn you when you try equipping a cursed item. I added all the metamorphosis effects to the wiki, check the cleric page.

Only if you don't count talents which go infinite, like liquid evasion.

By boosting the glyph Imeant wearing the Ring of Arcana.

Stronk and ded.

No, these types are just the mot common.

Try dropping an item, will it trigger the plant?

Yes, he can upgrade cursed equipment. It just must be identified.

That's not a simple answer since damage reduction provided by stone depends on your evasion and enemy accuracy. However, at low arcana levels stone definitely beats viscosity since the boost goes into increasing the portion of damage deferred first before providing any actual damage reduction. At very high levels, though, viscosity wins since stone is hard capped at 75%.

In your case specifically, damage would be reduced by ~80%, definitely outperforming stone.

If you found no scroll of Remove Curse in the shop, it's indeed a bug. Could you share version and seed?

Neither Wealth nor Arcana increases seed drops from grass.