Hello, Kiwis!

Haven't been an Air New Zealand flyer other than domestically for a while. Thanks to the current status match promo, I am Gold once more and looking to do LAX - AKL (8/10) and then returning SYD - AKL - LAX (9/19). All in Y but hoping to apply some RU's (see below!) I've got a couple of questions, any input much appreciated

1. Maximum baggage allowance on NZ5? I know I have 2x 23kg due to Gold status, is it possible to add another 2x (4 in total)? If so, is the 'second bag' charge applicable to 3 and 4?
2. Regarding RU's - I've looked through the successful/unsuccessful thread and it obviously drops of for data on NZ5 after COVID. What are chances like to secure Y - BP on the outbound via friends expiring Elite RU's? The same question for the return with my 2x Gold RU's and sub-question, are RU's per segment or flight (ie if successful can I upgrade SYD - AKL then AKL - LAX all on one ticket?)
3. Current J service - not too concerned about this as the bed and my own space are what I'm after!
4. Is there any way NZ5 would be under 105 SP in Y? I'd hope not considering the prices but it would mess with my converting Gold status match to full gold.

Thanks so much, regardless of service I'm planning on doing a flight and trip review including MIQ which might help someone else in the future!

See you in Koru Club!