PE Seats LHR-SYD

I have tried to search for the answer to this one but am having so many problems with this site at the moment, so I hope no-one minds me asking.
1. We're flying LHR-SYD in PE in Dec this year, coming back in Jan next year. Will we definitely get the newer purple PE seats?
2. How long is the stopover in Hong Kong as I'm finding conflicting answers.
3. Do you get to keep your seat for both legs as I've seen a trip report somewhere that suggested that once you get back on in Hong Kong you get a different seat?
4. Does the front row of PE on this route have extra leg room?
Thank you.
1. We're flying LHR-SYD in PE in Dec this year, coming back in Jan next year. Will we definitely get the newer purple PE seats?
2. How long is the stopover in Hong Kong as I'm finding conflicting answers.
3. Do you get to keep your seat for both legs as I've seen a trip report somewhere that suggested that once you get back on in Hong Kong you get a different seat?
4. Does the front row of PE on this route have extra leg room?
Thank you.