In my many trips to Europe (including Russia and Ukraine) and Canada, I have always brought my cash in and carried it around in a money belt inside my pants. Should I do any different in Taiwan?
30 years ago that might have been a good idea, but I guarantee most ATMs here will work with your foreign bank’s card, as long as you have a Visa logo or similar on it. All hotels and most larger stores accept credit/debit cards anyway. Carrying huge wads of cash around in a money belt just looks weird.
Well, atms are ok but banks back home will charge ridiculous exchange rates and fees. Try at least to limit your transactions and bring travellers checks not cash.
There is that, but assuming you’re on holiday and not living here, you can grin and bear it for a week or two. It costs me about GBP5 to withdraw NT$12000 (~GBP250) from my UK bank. My CC company charges a bit less. It’s offset somewhat by the fact that banks and CC companies (well, my bank at least) seem to give more competitive exchange rates than the exchange bureau. It’s worth paying a little bit extra for the convenience of not carrying thousands of US$ in cash.
Travellers checks are not accepted much here anymore, are they? I’d go with the cash, but distribute it more widely than one under-clothes money pouch, just in case you lose it.
I’ve not had any problems cashing or buying them at banks. Different from the US. Banks won’t take them unless you have an account with them. Instead they want you to use ATMs at $3 a pop.
I’d say that you do the same here. When I came last may with my parents, we had to withdraw from an ATM, and they charged us about a 10% commission to do so. Crazy.
The few times I came to Taiwan as a tourist never had a problem with thieves (I think that the banks are the ones that actually rob you…)
Money belts and such are usually recommended for areas with high pick-pocket type theft, or theft on trains, theft by people stealing bags, etc. Won’t find much if any of that here in Taiwan.
Depends on the currency. US$ are accepted by most banks, but I had issues with GBP ones - only certain banks did - and then only certain branches.
There was also a limit on how many you could change in one time - I had to go to a number of different branches to get the whole lot changed 
(I didn’t have an account at any of the banks, maybe that;s why?)
Dunno if it worked out much cheaper though - I had to pay commission on buying them in the first place, then again on selling them…