[quote=“jejunate”]The Chinese on the contract states that if I do not fulfill the contract, they will withold $30,000 from my pay. There is nothing about this in the English version. When I signed the contract I didn’t have any Taiwanese friends and didn’t understand any Chinese, so I assumed the Chinese and English versions at least contained all the pertinent information.
[/quote]
That sounds like a textbook violation of Article 26 of the Labor Standards Act:
An employer shall not make advance deduction of wages as penalty for breach of contract or as indemnity.
Article 78 sets the penalty (for the employer committing this violation) at $90,000 to $450,000. Article 79 also sets a $20,000 to $300,000 penalty for not paying in full (Article 22), in case they disguise it as something other than a breach penalty.
[quote]My question is should I give notice, or just go in on my last payday, collect my pay (always in cash) and leave, or should I give notice. I don’t want them to try and withhold $30,000 of my pay that I worked my ass off for. I won’t have time to fight them if they refuse to pay me.
Can they legally even withhold my pay? Especially with no mention of it in English? (There is a ‘Chinese language prevails’ clause).
I really like the school and they have been nothing but nice to me and have accommodated my every request. [/quote]
They tricked you into signing a fake translation with a “Chinese version prevails” clause, and at least one clause in the Chinese version is completely illegal. You can like them if you want, but they have no contractual obligation to return the favor. 
[quote]If I leave, will that cause me any problems if I ever decided to come back to Taiwan in the future? I love Taiwan, and don’t want to ruin my chances forever.
[/quote]
You should take care of your 2015 tax return. You’re actually supposed to file a few days (7?) before you leave, if you don’t plan to return the same year.
Read through the LSA and related regulations and make a list of every violation the company has or may have committed: against you, against other employees, and against the government.
Examples:
–tax: correct amount withheld?
–tax: official receipts?
–holidays: observed? (check Article 23 of the Enforcement Rules of the LSA)
–holidays: paid? (Article 39 of the LSA) (even if you’re “part-time”)
–leave: sick leave? etc. (check the Regulations of Leave-Taking of Workers)
–deductions: canceled classes? (check Article 487 of the Civil Code)
Once you have your list, consider how much of it you can prove. Then consider whether you want to quit by the rules of Article 14 or just make a fuss about all their violations and hope that they fire you. Either way, you’re entitled to severance pay (Article 17), unless they find a valid reason to fire you before you quit. (Did you pass your latest performance review?) If they fire you they can also be fined for retaliating against you (Article 74), but it’s lumped together with other fines in Article 79.
Whatever you do, make a formal declaration by email, citing all the violations you’re sure of and (if you quit) which subparagraph(s) of Article 14 you’re invoking. Also tell them that if they sue you, you will countersue and file complaints with all the relevant authorities (tax, labor, anything else you can think of). Even if they could win something from you, they would probably lose much more: payments to you, fines to the government, and legal fees.
You may find it helpful to go to your local labor department or branch of the Legal Aid Foundation for a free consultation. (People at Labor don’t always know exactly what they’re talking about, but they usually do. If they say anything that seems to contradict the law, get a second opinion or at least ask them what their information is based on.)
Of course you may want to file a complaint at the Labor Inspection Office anyway, after some reflection about how hard you’ve worked and how sincere their apparent niceness has been. 
Depending on how badly they’ve been breaking the law, you might be surprised at how much they owe you… 
It’s entirely reasonable to hurt your devious employer’s feelings by waiting until payday to quit. Whether it’s fair to your students is another question, but if the company is the party that broke the law, disgruntled customers should take it up with the company. 
Laws & Regulations: law.moj.gov.tw
Some more useful stuff is at the Ministry of Labor’s website (mol.gov.tw), but almost all of it is in Chinese.
