There is an offset current of 1/17 * FS mA, so if you add that to the peak-to-peak range of 9.375x2 = 18.750 mA, you get the full scale current. The offset is always there, so the comment of peak AC current relates to how much of that full scale current is available to your signal you are trying to generate, which is the 18.75 mAp-p, or the 9.375 mA peak.
Regarding output compliance, you can swing lower than the 1.5V, but you may lose a dB or two of performance.