#1 Ken, it's all fairly logical. Yes, you will have to pay a fee for temporary importation and for insurance.
The person you quoted was on a tight budget and did not want to pay these fees. As a result, they elected to ship the vehicle rather than driving on Korean roads in order to save money.
Riding on South Korean roads with a foreign registered bike IS FEASIBLE and VERY EASY. I did it 7 months ago with out problem. It took me all of 3 hours to obtain the necessary paperwork (customs clearance and insurance certificate) and I was riding out of Busan enroute to Sokcho the same afternoon.
Doing it in reverse out of Sokcho is just as straightforward. The customs and insurance offices are located right at the ferry terminal and are used regularly by both local and foreign travellers.
Feel free to PM me if you require further clarification.
Garry from Oz.
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