I will be studying Mandarin as from next semester- whilst still keeping my (basically) full time job. I will keep my ARC through my current job and study at NTU. Are there any tax benefits regarding studying?
If you are American, and you are working in a job that directly requires Chinese language (“it is required by your employer as a condition of employment” or something like that) it could be deductible. For me (as a language professional, as I laughingly call myself 
) trips to Taiwan are deductible as language maintenance, as well as any courses I might take while there, since my employer requires it. You need to be filing US taxes even though you are living outside the country (and it’s a good idea to show some US-based income if possible, so that you earn Social Security quarters just in case there’s any money left in the system by the time we retire. 
)
I have not filed Taiwanese taxes in enough years that I’m no longer current on what’s deductible, but I don’t recall any educational deductions for garden-variety working people back in the day. Getting both my parents to turn 70 was the best economic benefit I ended up with while living in Taiwan, tax-wise.