This is just the insmod phase so power isn't an issue yet... but it will be of course.

The messages you are getting should be warnings according to the wiki, but there is also a fix there too:

http://www.aircrack-ng.org/doku.php?id=r8187

When I was using this driver, it was with n810, so an older/different kernel. But I used ieee rather than mac and it worked fine. The mac approach is worth testing though, just another data point.