Go for it and let us know.
Sounds like the worse case scenario is you’ll be paying for language classes (or Kungfu classes) in order to stay. Now best case scenario is you’ll have a job as a secretary.
I’m pretty sure it’s illegal to any kind of work that’s not listed on your visa thing (including volunteer activities), but as long as you “stay under the radar” you shouldn’t have problems doing other work or volunteering. Suppose it’s a risk vs. reward type of thing.
If I were you I’d study Mandarin (and those other languages) and spend the rest of your free time doing whatever it is you want to do if you can pull that off. That’s might just be me though 
.
To get a working visa and work-based ARC, that secretary position better be paying greater than NT$ 49,000 per month or else it wil be rejected on the spot. Now, the company could say that it is paying you that much … in support of your application … but in actuality they wouldn’t be paying you that amount. This happens sometimes if employer wants you bad enough. Many won’t cheat on the paperwork but some will.
The other option is to work illegally and find a different method of payment. Payment options posted on these forums already.
Good luck.
Requirements for university diploma depend on which ministry you’re under for a particular job and what they want at any given point. All the people I knew who have worked in “other” jobs in Taiwan before have had to show a university degree, but that may have changed. The thing to do is to find out which Ministry would be issuing the approval letter for your work permit (probably Ministry of Economic Affairs, I would guess) and confirm.