Not so familiar with Dubai and Maldives but I can defintely recommend SQ for sectors from Maldives-SIN-NZ. In NZ, you've only got Air NZ to choose from. You can fly Air NZ from AKL-LAX and in the US, you've got either UA or US. Haven't flown US though so I can't really advise what they are like, perhaps others here can advise. Since you're *S, you can request for Economy Plus on UA flights.

I flew bmi once..... LHR-CDG and thot that it was a pretty good airline. though the check-in staff tore off the wrong ticket coupon on my colleague's ticket and he didn't know until we got to CDG to check in for the next flight. Had to pay EUR3000 for his 1-way back to TPE...and that's in Y!

I'm planning a RTW in May/June in Y too and will pass through NZ and then onto US....and UK too