Null rod is a one piece handle everything card. It handles all that needles are usually used for and then some. Its arguably better than needles in terms of what it can do. The problem with it is its easily counterable compared to needles which are somewhat easier to play around counters. Its also a turn slower, this can in turn make your goldfish slower as well. It all comes down to the metagame. If your meta has diverse hate cards (crypt, relic, EE, jitte, etc) and they are alot of affinity, vials, moxen, etc. null rod is relatively better. When relic and crypt are the only common hate cards needles are the better choice imo. Its just a matter of playing needle correctly, never name needle blindly, assuming what your opponent has is one of the more reckless plays with needle.

I haven't tested firestorm yet. I don't think its that good because it forces to discard, this is something that non-led dredge is designed not to do. You can easily outrace aggro decks anyway. The only match-up where i see it being fairly good are against merfolks and decks that run hate bears like teeg, jailer, meddling mage, etc.

Reveillark isn't suboptimal per se. It's good in certain match-ups just as sage is good in certain match-ups. Both are optimal in very different ways mainly because both require very different ways to play the deck. Reveiilark imo is better against blue where usually don't win thourgh the zombie hoard but rather through slow and consistent beats. Sage is better against decks you have to race because it wins faster in a fragile yet more explosive manner. You should play what you think works better where you play. Sage is just the preferred among the two because more often than not you'd have to race your opponent. I prefer sage because i really prefer winning through a race. The man plan for me is just the plan B for the deck. The reveillark for me is a slower clock although more steady.

@jimirynk: how big does the GGTs usually get with you most of the time? The deck doesn't dredge as much without the sage. The biggest ive had them in testing are 11/11 along with 3 zombie tokens and FKZ. I was still able to win later but the win was delayed by 2 turns due to my opponent being able to block the GGT.