I was tired yesterday afternoon so just replied with the basics.
I tend to steer clear of the opinion of gurus, particularly when they are selling supplements, and try to find independent information.
If the thyroid forum is trying to inform then it should be able to provide the evidence behind the claim. If all it can tell you is that it is the opinion of a practitioner known to make dubious claims and is based solely on clinical observations (this of course is licence to claim anything), then there is nothing to recommend it.
This claim just flies in the face of what is known about B12 uptake and processing. MethylB12 is the predominant form of circulating B12 and I am not aware of any studies showing difficulty in binding of this form to serum carrier proteins. I've done a quick google search but haven't been able to find anything of relevance.
There are rare genetic disorders where the binding proteins are defective, but this is for binding in general, not a particular form.
First check for hidden sources of cyanocobalamin in foods or multivitamins.
Other than that, high serum B12 is not uncommon.
Here is a recent review. Various studies quoted in the review put the incidence at between 12 and 18% in various populations where serum B12 was measured and studied.
The known causes are poor uptake, revealed by elevated MMA and homocysteine, problems with transcobalamins and various pathologies (cancer, kidney and liver disease). Most cases though seem to asymptomatic.
If you are not consuming hidden sources of cyanocobalamin it could be worth checking further since it can be associated with pathologies.
Impossible to predict. Depends on the cause.
I suppose it might be possible that lowB12 resulting in haemolytic anaemia could be associated with high serum iron. Otherwise I cant think of any link between high B12 and high iron, nor could I find anything by googling.
You need to do further iron studies to determine what high iron really means. Only about 10% of elevated ferritin is associated with iron overload. It can be associated with inflammatory conditions, something which would be relevant to many people on this board.
Here is a review.