I have the same problem, but on a smaller scale. I can actually log ingame but it takes ages to properly load lodestone.
It happens on all my network (even on phones and tablets) so you don't really need my computer specifications.
I guess a routing issue between japanese nodes and EU ISPs?

My Provider is Telecom Italia, and this is a traceroute:
traceroute to traceip.ffxiv.com (202.67.52.81), 64 hops max, 52 byte packets
1 192.168.1.1 (192.168.1.1) 1.266 ms 1.628 ms 0.810 ms
2 192.168.100.1 (192.168.100.1) 21.927 ms 24.626 ms 20.808 ms
3 172.17.145.141 (172.17.145.141) 21.238 ms 21.405 ms 20.743 ms
4 172.17.144.25 (172.17.144.25) 21.134 ms 22.349 ms 21.654 ms
5 172.17.9.161 (172.17.9.161) 29.263 ms 29.535 ms 27.712 ms
6 172.17.10.181 (172.17.10.181) 35.686 ms 35.721 ms 35.814 ms
7 172.17.10.69 (172.17.10.69) 39.963 ms 38.817 ms 39.277 ms
8 pos1-13-0-0.milano50.mil.seabone.net (93.186.128.97) 40.899 ms 40.127 ms 38.578 ms
9 te7-4.losangeles1.loa.seabone.net (89.221.35.146) 338.067 ms
te1-2.losangeles1.loa.seabone.net (89.221.35.128) 211.676 ms
te7-4.losangeles1.loa.seabone.net (89.221.35.146) 216.663 ms
10 pacnet.losangeles1.loa.seabone.net (89.221.35.186) 213.022 ms * *
11 po15-1-1.cr1.nrt1.asianetcom.net (202.147.61.186) 350.426 ms 327.816 ms 566.705 ms
12 * gi1-0-0.gw1.nrt5.asianetcom.net (202.147.0.178) 528.401 ms *
13 squareco.asianetcom.net (203.192.149.210) 528.059 ms * 358.282 ms
14 61.195.56.129 (61.195.56.129) 614.373 ms * 336.556 ms
15 * * 219.117.144.2 (219.117.144.2) 389.137 ms
16 * 219.117.146.149 (219.117.146.149) 527.721 ms *
17 219.117.146.129 (219.117.146.129) 350.342 ms 473.707 ms 614.177 ms
18 * 219.117.146.46 (219.117.146.46) 528.409 ms
219.117.146.38 (219.117.146.38) 327.798 ms
19 202.67.52.81 (202.67.52.81) 613.817 ms 616.298 ms 612.019 ms
Have fun.