Also read this and the Sword of Summer.
I liked it, but have to agree that a lot of time was devoted on the entire cast with basic information put in about the setting. Now that I think about after reading your takes, there are a lot of elements I recognize from other writers/works going on that I didn't think about at the time.
I did like the cat being his adopted kin's second. That was a funny bit with the certification in the middle of a lot of grim happenings.
The Sword of Summer is another foray into Rick Riordan's myth series but focused on the Asgardians. Loki is the villain natch, and it seems he is doing evil while still chained to his rock. The hero is the cousin to Annabeth Chase from Percy Jackson's books which ties things in with the rising of the titans and Gaea, and the Kanes battling Apophis. The Asgardians come across as living their lives while knowing their part of the world will be destroyed in the future which seems to be what Loki is trying to do to escape his rock. it is up to Magnus Chase and his allies to forestall that for as long as possible.
CES