All I can say is, cut down on the puzzles - and less of a huge map where parties have to have to find a specific item to fetch. Make it more focused and compressed like Cyseal.
Instead of cutting down the puzzles, they should just add alternates ways to solve them. Let's say you find a locked door: then find a key OR find a spell to destroy the door OR find someone who will open it for you. Just like how you have several ways of solving the murder case. Doesn't hurt the game and improves replayability.
And don't derail the players with too many details like telling them about THE END OF THE WORLD when they barely started on their first murder investigation.
This. I think they should be a couple more fights and xp-ing before the murder case in Cyseal. It would help new players to get the hang of the game, get some gold/gear and have some fun before tackling the tedious murder case and/or trying to get out of Cyseal to face numerous undead enemies. I'm afraid a lot of new players might get bored trying to solve the murder case for hours right after the tutorial part of the game, especially if they're not familiar with other "free-roaming" RPGs. And I agree that the "End of Time" first discovery should happen AFTER the murder investigation, for clarity.
Have the players find the first Starstone at the end of Evelyn's beach lair, for example.
