Okay, here’s something that may be important to you:
The restrictions on being a captain, radio operator, etc. that were quoted from on the CLA web page you initially linked apply specifically to fishing vessels, NOT to merchant vessels, and are found in the regulations quoted below. The “Item 8” mentioned below refers to item (subparagraph) 8 in Article 46 of the Employment Services Act covering commercial fishery. The provision concerning merchant and other vessels in the Employment Services Act is found in subparagraph 7 of Article 46, and so is not subject to these regulations. The fact that the restrictions on foreign crew type of fishing vessels under subparagraph 7 are specifically regulated but there is no mention of crew of the merchant and other types of vessels in subparagraph 7 supports an interpretation that there should not be any similar restriction for the vessels in subparagraph 7. By the way the translations I’ve quoted here are NOT my own – they are unofficial reference translations from, I believe, the CLA.
外國人從事就業服務法第四十六條第一項第八款至第十一款工作資格及審查標準 (民國 98 年 03 月 05 日修正)
(The Procedure Guideline of Transferring Employers or Jobs for Foreigners Engaging in the Jobs Specified in Items 8 to 11, Paragraph 1 to article of the Employment Service Act)
第 3 條
外國人受聘僱從事本法第四十六條第一項第八款及第九款規定之工作，其
工作內容如下：
一、海洋漁撈工作：從事漁船船長、船副、輪機長、大管輪、管輪、電信
員、動力小船駕駛人及其助手以外之普通船員工作。
二、家庭幫傭工作：在私人家庭從事房舍清理、食物烹調、家庭成員起居
照料或其他與家事服務有關工作。
The Procedure Guideline of Transferring Employers or Jobs for Foreigners Engaging in the Jobs Specified in Items 8 to 11, Paragraph 1 to article of the Employment Service Act
Article 3 For foreigners hired to perform the jobs referred to in Items 8 and 9, Paragraph 1 to Article 46 of the Act, their job descriptions shall be in the following categories:
1.Oceanic fishing jobs: performing ordinary sailors’ tasks except as captains, deck officers, chief offers, chief engineers, second engineers, engineers, radio operators of fishing boats, or pilots and their assistants of motor boats.
2.Housemaid jobs: performing house cleaning, food cooking, taking care of daily lives of members of households, or other related household service tasks.