@DM-Rocco I ran it for my wife and kids, so please don't be discouraged. Yes, it did take a lot of work and massaging on my part, but it was a fun experience overall.
Yes, my group had a good time with it too.
1. They hated the caravan chapter. It was long and tedious for them - 60 days of just watching and trying to figure out who the cultists were. Many of the encounters along the road IIRC had little to do with finding out who the cultists were. It is obvious where the caravan is headed - let them jump ahead to Waterdeep by ship or whatever and pick up the story there.
Obligatory counterpoint, though: for my group, the caravan trip was the highlight of the whole campaign. In fact, just a couple of weeks ago one of the players mentioned how much they enjoyed it--I think because they had some breathing room to play out inter-party stories at that point, rather than being rushed along by the plot.
The key, I think, is to figure out whether your players would rather get to the next plot point or have some "sandbox time." (Not a complete sandbox, as there are still scheduled events, but more of one than what comes before.)
I've also watched a lot of play-throughs on YouTube (etc.), and I know some GMs just flat-out tell their players who the cultists are from the beginning. That might be something to consider.
2. The dragon fled from the flying castle and was cared for my Talis.
3. Varis still had the mask when freed from the Yuan-ti, only to have Talis fly in and demand the mask from them. They were pretty beat up and figured it was best to have a prisoner and no mask than be dead.
Those are great ideas. I like the idea of building up Talis as a bigger character--she has a lot of potential to do more in the adventure, especially if one of your party has the background of being her friend.
(Side note to the OP: I recommend strongly encouraging your players to use the background options that give them ties to the story. It ties them into things right away.)
4. The back, white and green masks were all accessible and attainable by the party. Unobtainable fetch quests are frustrating.
Agreed, and also, the position on whether all of the masks are needed to summon Tiamat or just some of them changes between HotDQ and RoT. The "Enhancing Rise of Tiamat" thread has some good suggestions on how to adjust the final encounter depending on how many masks the PCs obtain.
