No. Sony WS623 comes with non-removable battery.
No. It does not have remote control.
Yes, you will get a pair of normal earbuds and a pair of swimming earbuds.
Yes, Sony NS-WS623 is meant for the rough usage and it is both - waterproof and dustproof.
Sony WS623 has 4GB internal memory and you can further expand it up to 16GB with the help of MicroSD card.