Erm, so it appears I have fixed this problem by repairing a different problem entirely. I have tried all the fixes I could find to fix this LSA issue. I had precisely the same problem with 10 events cropping up on startup etc.
Anyway, I had given up trying to fix it and resigned myself to maybe one day getting an update that'll fix it. I reverted all registry settings and any changes I had made back to what they were before.
I had a different problem - WLAN Extensibility Module Has Stopped.
I went into services, made the WLAN autoconfig service start up automatically (was manual), and disabled the (unused) ethernet on my laptop. Control panel > network and sharing > change adapter settings > right-click and disabled the (unused) ethernet.
Also for a separate issue, I disabled all forms of sharing in Advanced sharing settings which is in settings, not the control panel anymore.
Anyway, I did all this and both my WLAN error and LSA errors have both stopped!