Dev, your latest finds re dates for Aso Chou Lee show the inaccuracies that exist in Familysearch. Manaia's finds earlier seem more probable going by the dates for the children.
Not only that, but once NZ took over rule of W Samoa in 1914, no more Chinese came to Samoa, and those who had come under the Germans continued to be sent home. But some obviously stayed.
All of your family should be in the Western Samoan Government registrations, which started in the early 1900s.
As well as using the Search section of www.Familysearch.org
you should also use the library catalog section.
Go to Library, then Library catalog, write in Samoa in Place, then click on various headings until you get to Samoa-Civil registration.
There you will find
Birth registers for Savai'i, Western Samoa, 1905-1993 Savai'i (Western Samoa). Civil Registry Office
Birth registers for Upolu, Western Samoa, 1905-1992 Upolu (Western Samoa). Civil Registry Office
Marriage records for Upolu, 1919-1993 Western Samoa. Registrar of the High Court
Death registers for Upolu, Western Samoa, 1923-1993 Upolu (Western Samoa). Civil Registry Office
Click to see the print version of the holdings, decide which films you want to order, take down their numbers, then go to a Mormon Family History Centre, and order them in
I am not sure whether Manono comes under Savaii or Upolu, so you may have to try both. Generally these films are organized by date then by place (village) then by name. These films are apparently quite difficult to follow, according to some librarians I know who deal with them, but at least some of your family should be included somewhere.
There may also be other films there that could be of use.
Do you know what religion your family were? Most churches in Samoa hold records. If there is someone living in Samoa, whom you are in contact with, you could get them to visit the church office and find what is available. They could also visit the village itself, and see what is there particularly in regard to grave stones.
There are some records about Chinese in Samoa in the Samoan Archives at Archives NZ Wellington, but they have not as yet been transcribed. I am in Auckland, and only go to Wellington once or twice a year, and don't have enough time there to do much. If you have a family member in Wellington, who could be interested in transcribing things, I could organize it.