I don't think there is any change to your licensing with the image upgrade..You still retain the same license features as long as you downloaded the corresponding software.
Slight modification. for switch 2 (running 03.03.05) there is a hyphen before the switch number
Switch#copy usbflash0:[image name] flash-2:
this works well and much quicker than TFTP.
Just a note to make sure you have enough free space in flash memory on all your switches. I had one stack that would load the image file on the first switch and fail when trying to deploy to the other switches. Turns out I had a bunch of old image clutter. Once i purged the old IOS version files the upgrade went smoothly.