Mr. Hurst was pretty much an inconsequential character, IMO, in P&P. But here we seem to be finding him--or mention of him--in unexpected places. Consider the following:

~Mr. Hurst is rumored to have lost quite a bit of money in gambling. He also won a wager, betting on Mr. Parrish's imminent engagement. How far would he be willing to go--what drastic steps would he be willing to take--in order to retain what fortune he has? Is he susceptible to bribery? Also, did he make that wager based on speculation and his own observances or was he privy to information we wouldn't expect him to have?

~At the family conference in London after Caroline's experience with the knife, Mr. Hurst is the one who volunteers himself and Louisa as additional support in Caroline's hour of need. Lizzy believes he only has the wine cellar in mind, but does he? If he were involved somehow, wouldn't his presence be required with the rest of the group?

~At Netherfield, Mr. Hurst fumbles with the sherry decanter just as Mrs. Bennet mentions gentlemen losing their whole fortunes through gaming and Lizzy notices his hand shaking as he retrieves the stopper. Lizzy attributes this to excessive drink, but could it be that he's shaken by something else? Perhaps fear or the stress of impending bankruptcy?

~As she's sounding the alarm during the fire, Lizzy notices the haste with which Mr. Kendall hits the stairs. Later, she recalls that he was fully dressed at the time. She also notices that Mr. Hurst was more alert in responding to her warnings that she expected him to be. He even carries Jane out of the house to safety. This is a man known for his propensity to sleep more than the norm, so why does it seem possible that he was awake at this unlikely hour?

I'm beginning to think that if Parrish is up to no good, he may have used Hurst's weaknesses to worm his way into the family. If this is true, perhaps Parrish is requiring further aid from Mr. Hurst, using blackmail or some other means to force his continued cooperation.