They talk about instances at Venusta NPC: Krofin's Nest, Gludio Instance/Ashen Shadow Revolutionary, Crystal Prison (Baylor), Nightmare Kamaloka
Sometimes people do Altar of Shilen too, but nowadays it's a nosense instance.
Do something with the 16th anniversary coins, please. We just have it overflown in our inventory. Even my boxes have around 2000 and it's not possible to use them for anything because you can get 8x dice daily. Make it to be able to exchange for EXP stuffs at least or for additional event boxes. To have it any meaning.
If you go for ultimate PvE and slightly PvP choose GS. It's specifically the best way because of the skill power it gets. But if you wanna focus on PvP, trickster is the way to do the best dmg on the enemy. It's harder to exp with trickster because what GS has in skill power (which is a good for both pvp and pve) that yul has in PvP dmg only, so it has lack of skill power in PvE.
Sagittarius gets pdef and mdef from its specific skills, MS has skill crit rate and skill cd by its own skills.