No. Sony MBH20 do not have FM radio.
No. Sony MBH20 do not have volume control button. You cannot increase or decrease call volume but you can use your mobile phone's call volume control button for the same.
Yes, Sony MBH20 does have call ending button also.
Yes, You can use Sony MBH20 with Nokia 3310.
Yes, you can use Sony MBH20 with any Nokia mobile phone.