The magnesium issue:
The body ceases to function without magnesium. Magnesium is one of the critical electrolytes that the body needs for nerve and muscle (muscles include: heart, diaphragm/lungs, blood vessels, gastrointestinal tract, arms, legs, etc.) function.
Also, there are over 300 magnesium-dependent enzymes in the body that do things like make energy for you to be able to get out of bed, etc., digest your food, cellular metabolism, etc., that are also of critical importance. Some medications (such as Lyme treatments, pain meds, etc.) may not even work if some of these enzymes cannot do their jobs right...
My personal opinion is that magnesium is too important to not include in a daily diet or supplement routine. Yes, some may go towards the Lyme, but if no magnesium is going into the body, then you get Lyme damage AND magnesium deficiency damage. Avoiding magnesium isn't worth it in my opinion...