I'll preface this advice with a proviso, this is a public forum, all we do is offer our opinion, feel free to ignore, reply in kind, whatever.
You say, "I'll keep wracking my brains to see if I can think of anything else", my response to a runner who has been posting since 2008 and does not seem to have progressed much beyond a 5K is - Try looking in the Mirror, there's your problem.
what, only 1"? poor unsymmetrical you. everyone is unsymmetrical to an extent.
just try the old trick of taking a selfie and then photoshopping it so that you get your face with normal RH side and LH side as the mirror image, and do it again for the LH side, the 2 images you end up with will be weird and very dissimilar, because we're all asymmetrical!
All your other problems may be real but probably nothing to do with with symmetry.
You may be a fair weather runner, but still my favourite trail run of all time was through Epping Forest after a heavy snow fall, just the most beautiful scenery and fresh snow is the best surface you will ever find to run on.