Now, you mention 2 things that leave me wondering:
1- can you confirm that Dancin' the night away turned into How Could we still be dancing? First time I heard that.
Let's put it this way -- you can sing nearly every part of HCWSBD over the earlier song. The earlier tune is more complex in structure, but it has a nearly identical main riff, and a bridge section that sounds very similar (1:30 ... 2:30 ... ) as well. The instrumentation is similar too. Given that Brian has been known to reuse virtually anything he's written, the connection makes sense to me.
2- in another post you mention that Brian arranged the OCA vocals, though uncredited. Where did this info come from? As far as I know, it's all VDP's arrangements. Given Brian's talent for arranging and singing, and given his role in that album, it'd be strange if he did not come with a few ideas. But all I've heard and known about this is that Brian's singing VDP's notes. Never heard any of them state otherwise.
I once thought that too. But then this post from AGD came along:
http://smileysmile.net/board/index.php/topic,77.msg64040.html#msg64040As for Paley's departure, a lot was said in this place back then. And some theories were... well colorful. But the truth has not unearthed yet. But we know AGD knows the reason. Now do you know for sure? Because I'd like to know too.
I wouldn't say it's for sure -- just suggestive. I wouldn't expect anything colorful, either.