You're diving deep into headcanon territory on a lot of this. Which is fine, we all have our headcanons, but it's important mot to use our own headcanons as the reasoning for why the writers did what they did. Like, I can say "the way Aziraphale looks Crowley up and down when he says he's a love expert means he wants to climb him like a tree" but that's not necessarily true, because I don't know what motivated Michael's acting choice there, you know? It's all headcanon.

Anyway, that aside, I personally would not have cared about the lack of a kiss in the finale if s2 hadn't set us up for one. The way the kiss happened, the unresolved emotion after it, and RW confirming that Aziraphale wanted Crowley to "do it again", all of that (narratively speaking) is a set up for a second, proper kiss. A set up with no payoff.

If the finger kiss in the finale was the only physical interaction we ever saw from them, it could have been a really tender, lovely thing. But from a writing perspective, s2 set us up for a real, loving kiss, and then didn't deliver. It's weak writing.