On the transfer of points …..
I have BA and QR accounts which are linked. The vast majority of points are held in my BA account.
I have just booked a reward flight in J from the UK to Singapore on QR logged in to my QRPC account. The transfer of points from my BAEC account to my QRPC account was essentially automatic (I had to authorize it, but not initiate it) and instantaneous.
I have no observations with the process in the other direction, such as the OP, but my experience with BA to QR - on demand - was good and, presumably, very much how the system was intended to work when established