this is driving me nuts, so now i cant sleep

[KA9MOT]

While I couldn't pretend to be very technical about this I have had a few Fan Dipoles (and I haven't met one I didn't like) and I have learned a thing or 2 about them. We regularly used one of my extra fan poles for portable events as well as field day in different arrangements.

Center (Feed) Point at 15 feet? It will work reasonably well, but not even close to one that is installed higher. You can install the legs at right angles to the other, but you can not install them side by side as indicated by the blue lines in your drawing.

I wouldn't worry about those power lines too much, and with your limitations you might be better off to consider a vertical or even a loop.