Yes, it is.

It is possible for max. 60days without visa in case of travelling purpose.

For other purpose (education, business, visiting etc.), please acquire appropriate visa through Russian Embassy for entry.

Recharging battery is paid service and can be rechargeable at Information Desk.

Yes, it is free.

Yes

Russia: 65,000 Korean Won for one-way / 130,000 for round

<Custom Clearance for bicycle >

For high-priced bicycles (more than $800), it is recommended to fill out the Temporary Export Declaration to custom on ticketing and get confirmation from custom before boarding.

If you leave the country without customs declaration for high-priced bicycles, import tax may be incurred upon return.