Sony MBH20 comes with Sony battery only. As per company, it offers up to 100 hours of standby time and about 7 hours of talk time.
Yes, You can use Sony MBH20 with Nokia 3310.
Yes, it does have call receive button.
None of the users have reported any heating problem about Sony MBH20.
No. You cannot change the battery of Sony MBH20. Sony MBH20 comes with in-built battery.