I have provided you with a study on custody outcomes in Taiwan published in a leading, peer-reviewed family law journal. What more can I do? Your experiences are not invalid, but surely not representative. The main issue appears to be foreign nationality or inability to communicate in Chinese. That is something I would definitely agree with - not with gender as a factor however!
One way to start is using the search function of Forumosa or Google.A few simple queries for “foreigners open company Taiwan” or “foreigners real estate Taiwan” already produces some good results.
As for affordable legal advice, lawyers are equally expensive for foreigners and locals. The Legal Aid Foundation, several county and city offices, as well as a number of legislators and city councilors offer free legal advice. The Legal Aid Foundation also offers free court representation in many cases, usually requiring a low-income household certificate obtainable from the local Household Registration Office. Foreigners can also procure this document.
Obviously it all comes down to Chinese ability. I can sympathize with someone who has just arrived or stayed for just some years. But I cannot feel bad for someone who has resided in Taiwan for 5, 10, or even 20 years and cannot get himself (or herself) to a level of Chinese proficiency to manage such affairs. Particularly when we are talking about people on APRC or those who even demand dual nationality.
Foreigner involved. Again: I do believe Taiwan courts have a general bias against foreign spouses. But that bias exists irrespective of gender.