Hi;
Yes, the two ANs a person encounters with NF-2 do not need to occur at the same time. Mine were discovered 18 years apart. In fact, initially, a person doesn't need to have bilateral ANs to be Dx'd NF-2. A related tumor in another part of the body and 1 AN is sufficient for Dx.
Could be MS or NF-2 if one considers an AN might be affecting the trigeminal nerve or the person has developed neuropathy so as to cause the burny, tingly, prickly, hot, numb feelings.
It seems to me there's no doubt you need a head MRI!
You were quite young ( <30 ) for the first AN which is but one indicator of being NF-2.
Would say I think MS is more common and do bear in mind you report true vertigo ( uncommon in AN ) and blurry Vs, but blurry Vs can be caused by vestibular problems as well.
Re, "regrowth question"; You need an MRI to rule out Schwannoma, or Dx excessive white matter of MS.