About the Ball, the safety of the angelic embassy and the importance of discussing plans
You know, I think there was actually one more reason for Aziraphale to have a ball in his bookshop. Not just for the sake of having a dance with Crowley or make Nina and Maggie fall in love – though, of course, the idea of it happening was present and pleasant for the angel.
I first thought about it few days ago while rewatching episode 5. Do you remember how insistent Aziraphale was on making everybody going to the meeting, stooping to direct temptation to achieve 100% attendance? Yes, yes, I know, it was for the ball where Aziraphale planned to dance with Crowley and (maybe) make a step further in their relationship. But if you think about it - yeah, Doctor Who fan provided music, but why would Aziraphale need a magician and his partner for this meeting to present? Even if both magician and DW fan had declined, there still would have been Nina, Maggie, Mrs. Cheng and her husband, French restaurant owner, Mrs. Sandwich, Mr. Brown, some other people…it actually seems the whole street except for first two men agreed to come without any problem. It’s not like two random people would make any difference – neither for Crowley (he doesn’t even know or care about them!) nor for Nina and Maggie.
There also was that subtle face change, when Nina and Crowley couldn’t see Aziraphale – he’s suddenly a lot more serious than during his talk with Crowley, and even a bit concerned about something?
Now, we know (and Crowley doesn’t) that Aziraphale is aware that Shax knows about Gabriel. It seems Aziraphale totally forgot about that danger focusing on the ball….or not?
You see, while the bookshop was a center of demons’ unwanted attention, it was also (paradoxically) the safest place for mortal to be in the Whickber Street at night in case demons attack (and it looks like they only attack at night). In theory, at least. We saw how demons followed unassuming Maggie while she was heading to the bookshop – hardly with good intentions. We also know the bookshop is technically an embassy and thus safe from demons – unless you go out the doorstep on your own like Mr. Brown or invite them like Maggie. Otherwise all demons could do was breaking the windows and shouting some nonsense from the street.
Actually, even Crowley agrees the bookshop is the safest place for Nina to be at that night:
So that’s can be why (I assume) Aziraphale was trying to invite everyone on the street – he knew there was a chance of Shax arriving, and had in mind people of Whickber Street would be safer inside. That’s why he didn't bat an eye when Crowley told him about demons outside – he knew it might happen and actually took measures! He even explained it!
There is actually nothing to worry about! Humans will be too busy the whole night, dancing, talking Jane Austen style and trying to figure out which guest is the seamstress and which one is the seamstress – and wouldn’t even notice something unusual happening outside. In fact, Aziraphale and Crowley might even dance (while Shax helplessly looks at them from the window) and even kiss – what can Shax do, with them being inside an embassy? The whole London might be destroyed, but an embassy will remain safe – like at that concept picture:
….At least he thought so. You all know how it ended. Demons broke the window, Mr. Brown went outside and was taken by demons (so, ‘keeping humans safe’ idea failed), and only then Crowley bullshited their way out by convincing Shax ‘civilians’ should be evacuated.
You see, it wasn’t a bad idea, per se – using available props, like demon-proof building, or summoning/discorporating circle later. But it was a terrible plan, as it didn't take into account the various subtleties – would demons be able to draw attention to themselves even if they can’t enter? How humans might react if they notice something and how to keep them safe at this case? What to do in case demons stay – they definitely can wait for a long time – longer than humans will agree to stay for sure?
And you know what could have made this plan better? Discussing it!!!!! With Crowley!!! With Crowley actually discussing it, not just disregarding it, cause the idea is good, it just needs some revisions. That’s why there is such thing as peer-review, for God’s sake, to see errors caused by cognitive distortions!
(And then Crowley in his turn ignored Azirapjale’s attemption to suggest and discuss some plan – maybe about activating the circle? That actually wasn’t a bad idea too, but shouldn’t have been the whole plan)
But if they discussed the demon-proof embassy plan, Aziraphale would also have to mention that he had met with Shax, and he didn't want to talk about it - for whatever reason. Probably the same reason why Crowley kept silent about his meeting with Beelzebub, Shax’ threats, and Jim's "prophecy" of the tempest.
A severe case of miscommunication disease, the main villain of these series; The Metatron is no match for it.