I found the Kingdom maintenance really boring and annoying. I would try to incorporate a mini-game into it instead of a slog of dice rolling. Maybe something "Settlers of Catan-ish." At least reduce the number of city counsel members or something? Or maybe deal with it all via email and don't waste valuable table-time on deciding where to build a garbage dump. Wannabe fantasy "Civilization" with decisions made by committee just wasn't fun for me.
But I only played the first two (of six?) sections.
Oh the boards you can find Hargulka's Monster Kingdom, which has some terrific fan changes to book 2. I like many others also plan to work Realm of the Fellnight Queen's module into it and change details to link into big N's forshadowing.
More political intrigue, less math. If you're playing at a table, bring a laptop tablet with a spreadsheet that can calculate all of that quickly, and don't let the party spend too much time on decisions. And definitely assign various checks to appropriate players so that everyone has a chance to roll... but don't be a Nazi about it. Players can be really superstitious about dice, so if someone is scared to roll, don't make a big deal about someone else rolling as long as the game keeps moving. 5-10 minutes per month should be more than enough time, especially if everyone comes to the session with an idea of what they want built. Early on, there might need to be votes, but keep them informal and build the first thing a simple majority of the party agrees with... and don't be afraid to offer suggestions from the NPCs if the party can't pick something. Keeping it flowing is key, because then you can keep it a lot like combat. Then use the extra time to flesh out interesting events and make sure *everyone* can participate. Sure, the Ruler needs to seal any diplomatic treaties, but the Grand Diplomat negotiates the treaty, the Spymaster discovers dirt you can use for a better deal, the Treasurer appraises the economic repercussions of the treaty, etc.
Moving along... introduce Nyrissa early, and keep her as a malevolent presence. Whatever you do, don't let her existence surprise the players or they will come up with their own goals, and will resent you trying to railroad them with some faerie queen they've never heard of. Book one has the unicorn, but that's easy to miss, so give them other opportunities. Book two has Hargulka, so have him actually worship her as a divine being. An altar to a nymph in a troll fort should get the players paying attention. Book three contains the area where Eranex from Dragons Unleashed, who might make for an interesting ally.