No. Sony SRS-XB10 does not have the memory card slot.
Sony SRS-XB10 is a mono speaker. However, you can use 2 SRS-XB10 at the same time with your device and they can perform as a stereo speaker.
Sony SRS-XB10 has 5W sound output capacity.
Yes, Sony SRS-XB10 does have the inbuilt microphone.
It takes about 2 hours to fully charge the Sony SRS-XB10 speaker.