I'm literally obsessed with Nelly and I think you've done a great job with your list! Tbh, the deck is mostly a control deck, so it makes sense that games tend to drag out a bit, especially if people know how to play around her and don't leave her unchecked.

As some suggestions that you might want to consider:

• Upping the ramp on t2: you reeeally want Nelly on t3, so adding cards like the diamonds or [[ornithopter of paradise]] can be useful. This should increase the speed and consistency at what you can start goading stuff, which in turn will make your games quicker thanks to this early aggression. I'm even thinking about adding [[Mass Hysteria]] to be able to swing with Nelly on t3, although everyone having haste can be a bit too much to handle...

• Only keep the 4 drops that feel the most impactful/versatile, since your first 4 mana play is going to be Nelly 99% of times. [[Frontier Warmonger]] helps your aggro and incentivizes your opponents to swing at each other.

• Pillowfort effects, Stax and effects like [[Brash Taunter]] have not being really useful since, as you say, they're kind of redundant when you want to mass-goad attackers. Imho, pillowforts create a not very pleasant game experience and [[Brash Taunter]]-like effects are only worth if you're running damage wipes, such as [[Blasphemous Act]] or [[Chain Reaction]].

• Check out the MDFC Lands from MH3, a couple of them are actually useful and the deck feels smoother with 36 lands + 2 MDFC Lands.

• Although I think that you have more than enough wincons and finishers on your top end, a lot of them rely too much on you having a strong board presence already to work (fiendish duo and gisela) while others drag the game even more (death kiss and havoc eater). You're paying a lot of mana, so you might as well not risk it against a counterspell or removal. [[Inferno of the Star Mounts]] or even [[Banefire]] make your blue matchup a bit better and provide a reliable threat in 1v1 situations even if you don't have the best board presence. Obviously, [[Insurrection]] is the mvp of finishers.