After the PC:s foil the furious frogs, they get to battle the brutal bandits. It looks a little railroady so far, but once we get into the Moathouse proper, the PC:s will get more choices. If we assume the group is new, running them on rails for the first two encounters might not be bad.
What's supposed to happen here is that there are tons of archers firing at the group from inside the Moathouse, while the melee enemies (The bandit leader Enzer, a few regular bandits, and a barely tame rage drake) confront the PC:s in the courtyard (area #3). What actually happened when I ran this was that the whole group ran from the drawbridge to the stairs. Taking a double move gets you there in a round, so you can imagine the cluster that formed in the main hall (area #4).
With smart players, you too should expect the encounter to mostly take place there. A subversion would be to have the drake chained in the courtyard (weakly enough to break free when the PC:s arrive).
Anyway, one of the players decided to try to talk to the bandits. Not a bad idea, I thought, and whipped up a skill challenge. (That's the beauty of PbP: If your players surprise you, you have a day or two to come up with a comeback.) There was probably going to be a fight either way, but if they succeeded Enzer would spill some clues about the lower levels before attacking. Otherwise, there just aren't that many.
Some fateful rolls later, there was a fight. Enzer is a decent distraction, the rage drake is nifty, the archers do their job even in close quarters. However, the Human Bandits are rolling +4 attacks versus AC:s of 19 and 21 (in my group, which wasn't overly optimized). That's just silly. This was certainly a harder fight than the frog butchery, but in the end, the PC:s will prevail.
As I mentioned last time, consider moving two or three of the frogs in here too. Maybe they barge in after the PC:s cross the drawbridge, adding another incentive to stay in the courtyard.
Next up: The Moathouse basement is a nasty place.