There’s no out of the box network support, no. Dialogue lines in MMOs aren’t normally sent through the network, so I would suggest sending node ids from client to server every time you select a dialogue line. Clients would have authority in navigating the dialogue tree (so no delay occurs), but the server would have to check if the navigation that is happening is allowed, and if so, would fire necessary events.
Depends. There are multiple ways to go about it depending on how frequently you want animations to play, and if you want specific montages to play or just a random chit chat animation to play every time the NPC says something.
If it’s the former, I’d suggest each node to have an enum chat_animation {Angry, Casual, Casual 2, Amused, etc}, and to have the UMG widget trigger that animation on the NPC every time a new NPC line is displayed. I can go into more detail about that if this is what you need.
And if you simply want to play a specific montage, try doing it through the event system that is described in tutorial #2.
Make sure something is connected to the NPCActor pin when spawning the dialogue widget:
https://i.gyazo./587b72f6c4d9ea97f50bb5357869b179.png