As a new DM in Wrath of the Dragon Queen I was a bit overwhelmed with a likewise new group of players. I was waiting for the party to get into town and was going to have the dragon attack when they get to the keep. 

However, I forgot and it slipped my mind. Would it work in the story if I had Lennithon held captive at the camp in episode 2? Maybe a brood egg laying space?i was considering motivating the party to release him as a distraction to aide the monk rescue. 

I wouldn't risk the part getting in a fight with Lennithon.  I just finished up Horde of the Dragon Queen and I found having a dragon pass over heard, or roar in the distance was a great motivator to keep the party focused on their task.

Did the party see the dragon attacking the town?  That might have been enough.  

Or, as you said, you could have Lennithon at the camp.  Maybe as the party approaches Rezmir is seen walking away and the dragon flies off?  Or maybe perched on a hill nearby?  Or if the party hasn't left you could run that attack after the army has left.  

Fun campaign, enjoy it

I want to rearrange the bridge between episode 2 and 3 and make it more of a payoff. They don’t go get info and come back only to be sent back to camp. If they will be railroaded anyway there’s no since in making them disembark for  a connecting  train, ammarite?

The party is fairly sneaky and wants more non-combat action side of the game. They are newbies and don’t mind being lead to the objective as long as they get to do different things along the way  

1. Party follows the trail to the camp

2. Infiltrate and find Erlanther

3. Erlanther imparts his plan and tasks the PCs or frees them all and continues his plan (because I guess they need the help at that point)

4. Party gather my written in antidote items and the story information (pre-written note cards because otherwise why bother?).

5. Wake up a sleeping dragon and quickly GTFO to the high grass. Maybe he remembers later for better or worse? Imagine a pride hurt dragon or a a dragon reacting in some other way.

6. Skip the hunters and run the hatchery.

I’m thinking the dragon is drugged to sleep and under lite guard. When they come upon Erlanther he has a plan but he has run into his present slight complication. He knows the PCs can give the dragon some sort of inhalant and it will wake up in 3dx minutes. The monk, in his infinite wisdom of all things dragon cult, could direct the players to gather a few items around the camp to make the inhalant. I could frame this as plausible since the camp is in disarray. It gives the PCs framework to success while they gather info. I can just drop the three or so items in as they gather info until they are bored or the action runs it’s course. 

Erlanther tells the PCs he plans to track the disoriented dragon back to its lair alone. Too many would arouse it’s suspicion. Instead, they should lay low for some hours in the bush because they camp will break up shortly and there is a very interesting cave he was going to checkout himself. Erlanther is playing the as written brave and daring personality to do this. It also gives him a way to be back before the PCs to give them the horses for On the Road. 

Sounds like a good plan.   I like the idea of collecting ingredients from around camp.  The hatchery was a nice change for pace for them, as it is pretty standard dungeon crawl, which they won't see for a while.

My players were mostly very experienced and with the exception of one sneaking in to camp the rest stayed put.  They knew they couldn't take the camp when populated so they weren't going to try.  I poked them a few times, and dangled some bait, but they weren't going for it.  They did create a diversion and free the monk, but that was it.  

So... after some reading and studying I decided that the party will be sent from Greenest by Erlanthars good friend Gundren Rockseeker after a night of revelry and pre-campaign bonding. Pretty sure there will be goblins and a dead horse on the road...and an old well... and not a dragon horde....

A good portion of the campaign has the players following a large amount of treasure.  I am finding it amusing that every now and then they get their hands on it and treat it as if they are taking from the Dragon Cult, or Tiamat's horde.  I'm waiting to throw out, not directed their way, in Rise of Tiamat a discussion between the allies about ways to return the treasure to it's rightful owners if/when this is all over.  With the players sitting right there with 10,000's in gold, gems, and treasure sitting in their bag of holding.  Hopefully they feel a little shame.