I thought more about the ICBM statement, and it is 100% an outlier.
Just saying that she is more dangerous than an ICBM doesn't mean that she scales to it in AP. He could be saying that she is more dangerous than an ICBM because she can open portals to other worlds. If I knew someone who can open portals to other realms full of extremly dangerous monsters and send people into that other realm, I would consider that person pretty damn dangerous, even if they could barely hurt a fly in terms of AP.
Aside from that, El has not really shown any feats that come close to an ICBM's level of destruction. She struggled fighting against the Mind Flayer's Proxy, who is baseline Building Level at best. She had trouble throwing Billy through a Wall.
Her freaking out at Hopper only caused some windows to break.
She struggled to break down a metal door. She struggled to kill Dr Brenner during their confrontation. Yes, she was weakened due to the sedative, but if she really was as powerful as a ******* ICBM missile, it should have taken her no effort to kill him, even when weakened. She struggled to turn the Demogorgon to dust.
It took her a solid couple of seconds to kill a demodog. If she was as powerful as a missile, she should have been able to kill it instantly. A ******* nailed baseball bat can kill them in a few strikes, yet supposedly someone with the power of a missile still took several seconds to kill one?
After regaining her powers, she only sent some guards flying up a few meters and some lights to spark.
Simular feats have been calculated at Street Level.
Most of the feats I just listed fall within 9-C to 8-C territory, and most of these feats required her to use absolute full power to the point of where she passed out or were done during a state of extreme stress for her, when her powers would be at their most powerful. If it takes her genuine effort and requires her to be in a state of fight or flight to accomplish feats within the 9-C to 8-C range, how is her telekinisis suddenly scaling to a warhead not an outlier?
Her environmental destruction should still be High 7-C because that is environmental destruction that portals are capable of causing, not how much AP it takes Eleven to make portals or how powerful her telekinisis is. If Eleven and Vecna both already had Tier 7 telekinisis, why did Vecna need to use the portals to destroy Hawkings and not just find a way into the real world and destroy it himself with telekinesis?
Eleven and Vecna should still have "At Least Building Level+" telekinisis due to that being how much energy is required to open the portals and due to Eleven fighting off the mind flayer and it's proxy while at her full power, but the ICBM feat should almost certianly not scale. Unless if you want to argue that the Mind Flayer & its Proxy, The Flayed, Dr Brenner, Demogorgons, Demodogs, and the guards in the facility are all capable of tanking attacks from an ICBM missile.
From what I can tell, Eleven's telekinesis is about Wall Level - Small Building Level while holding back, At Least Building Level+ when panicked/bloodlusted, and Large Town Level+ via environmental destruciton with portals.
TL;DR: ICBM missile statement is an outlier and has pretty much no proof to back it up.