I must have missed your questions, so I will try to answer some at least.
I can't give you an opinion on your first two photos - M. albilanata and M. albidula. To me your plants look very similar, and certainly the albilanata is too young to be sure . It should develop a lot of axillary wool, but your hasn't yet. It is possible that the second is a form of M. haageana, whch M albidula is included in now.
The next is M. hahniana, but ssp. woodsii has dense white wool and some hair like bristles at the apex. Yours has, I think, too many bristles and too much hair, and the spines are not dark enough to be ssp. woodsii. I'd just put it as M. hahniana. The ssp bravoe has shorter central spines and a bit less hairy.
And your last one, in the thumbnail photo, is M. magnimamma.