To get the khz, find out about the BASS_ChannelGetAttributes function, it will return you the freq (in hz, so you divide by 1000 and you get khz).
And this way to get kbps:
BitRate := Round(BASS_StreamGetFilePosition(strm, 2) * 8 / BASS_ChannelBytes2Seconds(strm, BASS_StreamGetLength(strm)) / 1000);