Bumping my own thread in search of a bit more advice, clarification, and encouragement

... my travel agent has forwarded the itinerary I decided on to BA for pricing. Because of a change or two in circumstance I've now
almost settled on this, starting in early September:
GIB-LHR-DXB-LHR-SYD-AKL-SYD-PER-HKG-SIN-HKG-NRT-JFK
[JFK-LHR, a few months at home/work, then back across the pond for]
JFK-YVR-DFW-BOS-ORD-SFO-LHR-GIB
If I understand the rules correctly, this:
GIB-LHR 2030-2215
LHR-DXB 2140-0730
lets me sleep in my own bed without a waste of a stopover 'cos it's 35 minutes short of 24 hours ^ and I assume the rule applies to scheduled times, not flight times, ie if LHR-DXB was cancelled or delayed to later than 2215 I wouldn't have broken the rules -- is this right?
If so the only things I'm worried about now are whether GIB-...JFK-LHR in just over 5 weeks is a bit too ambitious

and the old chestnut of who to credit the miles to

. I opened an AAdvantage account without yet signing up to the plat challenge as I'm still leaning towards piling all my miles in one BAsket. I figure I'd make silver and 920 TPs. With that 55k starting balance, a job that's about to take me transatlantic on BA a few more times per year than previously ( ^ ), and if I can find the funds to do JFK-LHR-JFK in a TP-earning cabin, I reckon I'm doing the right thing.
Am I?