Hi Everyone
I have an offer to teach English in Hsinchu.
My question is can I come visa free (as an American citizen) and apply for my ARC in Taiwan?
What documents are needed for an ARC? Must they be original copies?
Can I work while my ARC is processed? What are the potential consequences?
Have you tried looking at the immigration website? It’s 100% English and lists all requirements for applying for an ARC.
https://www.immigration.gov.tw/mp.asp?mp=2
If you don’t find anything there, there’s a boatload of information on old threads here. Use the search function on the top right next to your user icon.
‘What documents are needed for an ARC? Must they be originals or copies?’ 
Helped you out here a little. It can be copies but they need to be notarized/certified by a TECO in the US.
ARC comes after work permit. Follow the link in the previous post, all needed knowledge is there.
yes, you can, if you have a work permit.