http://www.imperial-library.info/dfbooks/b105_alt_redguard.shtml mentions "Arch, in the province of Seawind". Is there anything more we can deduce from Lore about it?

Would it be correct to assume that it was destroyed? Your thoughts here please.

It would be correct to assume that it was either destroyed or did not exist to begin with in the current incantation of lore because the name and surrounding premise is lame. if you want to take everything that [incorrect] book says at absolute lore, then yes, it was destroyed. flooding lead to the submersion of most of the continent, it would certainly submerge a port city.

^ Or maybe it could be called "Arrusha" now (which still exists in Yokuda)?

I know the Redguard Lore from DF is made out of fail compared to later installments, but it's all we have. Or is it?

theres nothing to tell one way or the other. so do with it as you will, as long as its plausibly cool and stuff.

I don't think I quite understand what Yoku society was like. (Disregarding the cheap samurai movie concept).