what depth increment should I use for pocketing and profiling with the 1/2" end mill?

The pocketing depth per pass will depend on the hardness of the material, the router/spindle you are using and on the melting point of the material. Use the feedrate that you would normally use for the size and type of end mill. You will need to test the depth per pass, starting at the full depth of the pocket. The spindle should have no problem, but if you are using a router, then it may bog down, so easing up on the depth per pass is recommended. If the spindle/router has no problem at the depths you are using, then you need to evaluate the edge finish to determine if it is acceptable. If it is not acceptable, then ease up on the depth per pass. Keep doing these steps until you have the finish and precision you expect.