score:5
You can buy residential (not commercial) property if you hold an Alien Registration Card and if Taiwan nationals are able to buy property in your home country.
You are generally not allowed to buy for profit, buy multiple properties etc: only buy a residence for personal use.
You are also "required to apply to the Ministry of Economic Affairs for approval of the intended purchase" with regard to the above criteria
And more importantly a Taiwanese guide to the relevant Taiwan law, and it's implementation, along with the actual act it refers to The Land Act