Hey!
I think this game provides very nice solo experience.
As for the MMO aspect, i think it can be improved.
From the top of my head, i can suggest 2 things.
1. Party finder
Basically you can copypast that feature from FFXIV.
It's a window, where you can post an information about your group, what dungeon you are aiming to complete, which party composition do you want.
Also you can type text description and requirements.
Althrough, i think one critical alteration should be made.
Parties can only be created, posted and seen only by a players in the same map, where instance the party is heading to is located.
It will eliminate "why should i venture into the outside when i can sit in the city for the whole day" problem and will make the world more alive.
2. Stimulus to visit player houses ingame.
Currently you can visit houses of guildmates or your friends without installing addons as i understand.
So would be cool if you could choose which house to visit.
Maybe also include some ways to advertise your house and host parties and such.
Maybe housing endorsement system.