I am starting to plan our family's RTW trip for 2019 and have following in mind:
February 2019: AMM-LHR-BRU
July/August 2019: BRU-DOH-CMB-SIN-oMNL-HKG-TYO-HNL-LAX-oSFO-MIA-PTY-MIA-LHR
December 2019: LHR-DXB

Itinerary is priced around €22,000 for family of 2 adults and 2 children <12 years)

Questions:
- is there a cheaper starting point then AMM for my itinerary? (I live in BRU)
- am I correct that I can book the itinerary as from 350 days before flight dates, but only have to pay once the tickets are issued (at least 28 days before first departure) ?
- hypothetical question: can I skip the last flight (LHR-DXB) without penalties?

Thanks