I'm having the same issue. Appears to be a bottleneck in the network somewhere on the SE side.

I've gone as far as putting my machine in DMZ just to see if it was a traffic problem on my side.

I can however ping the login server and don't see any latency there, so I'm not sure what this is all about. Would love some input from SE on this one.

I've tried putting the folders into full access, which isn't doing anything as they default back to Read-Only, Tried re installing the launcher, DMZing my machine, Checking Port forwards, rebooted computer, rebooted network, hell I even tried logging in on my PS3.

ISP is not blocking the ports used by FFXIV so I don't know what else could be going on other than the login server being difficult for some reason.