According to datasheet of TRIAC driver optocouplers MOC3041 it can bear 400v 1A, is that means we can use it without triac if the load draws current lower than 1A? if NO why? i tested it for a small 5W LED lamp and works well but dosen't work for 30W CFL lamp. Other question about this driver is: I know what means Zero cross detection but what dose Zero cross detection INSIDE this optocouplers?
The peak current rating is 1 amp. Read the data in the snippet you posted. That peak is for 100 us repeated 120 times per second. This is not the continuous RMS current rating of the device.
If you look at the datasheet it shows the Triac current should be a minimum of 0.4 mA and a surge maximum of 1 A.
Continuous current for the Triac is not stated, but from the graph below you can see that the power dissipation of the device will rise rapidly due to the T1-T2 voltage.
Providing you can keep the device within thermal ratings I'd suggest you could get 200-250 mA load current from the device.
The zero crossing detecting is these devices is a very simple voltage detector. If the AC (t1-T2) is above +/-20 V then you can't turn it on no matter what the LED current.