is it not possible for a very close encounter with a solar flare to lead to a sudden and dramatic pole reversal as the flare sweeps through the atmosphere and the earths magnetic layer also resulting in a change in the earths rotation. what are your thoughts?
The Earth's magnetic field is from convection currents in the core.
I think it would be quite unlikely for a solar flare to be able to change those, Solar flares are quite able to damage satellites and even power systems on the surface of the Earth in extreme cases but to affect something the size of the Earth's core shielded by hundreds of miles of rock seems to be stretching it a bit too far.
It is established that the polarity of the Earth's magnetic field has indeed 'flipped' many times throughout it's history. However, it is not currently thought to be connected with the Sun's magnetic field, but rather by chaotic events or disuptions from within the Earth.