Yes, Samsung Gear Fit2 Pro can be used with any Android or iOS devices with Bluetooth connectivity of 4.2v or higher.
Yes, Samsung Gear Fit2 Pro does come with the charger and a charging dock.
Yes, you can receive text and even can respond from the watch with some pre-programmed responses. You can see the call alerts but you will require either Bluetooth headset or the actual phone to talk. There is no speaker or mic in this band.
No. Samsung Gear Fit2 Pro would not be able to measure blood pressure.
Yes, you can. Samsung Gear Fit2 Pro has 4GB internal memory and you can store as many as 500 songs.