That depends a lot on the sourcing. Blanks (as opposed to Pariahs) tend more towards just being unpleasant in most sources. See Eisenhorn. Full blown Pariahs are where you tend to get the really debilitating effects.
Didn't Eisenhorn who had some low level psyker abilities feel pretty ill when he was in proximity to one of his psyker underlings, Bequin, was it, IIRC he sort of loved her, but close proximity to her basically have him a headache and made him nauseous?
And he is a fully trained inquisitor with lots of years of life experience that probably ahrdened his stamina and resilence to bad stimuli, read torture, put something like that next to a young kid and the results will probably be worse.
Well yes, raising a human psyker in the webway would be a good idea. Except it assumes consistent, long term, access to the webway.
Well, the Dark Eldar and the Mechanicus already have an IIRC understanding of sorts, since they helped the cogheads to fix up the golden throne according to one book.
Maybe parts of the Inquisition, too.
And humanity does have a lot of undesirables that can be sold to the degenerate knife ears in exchange for some access, criminals, heretics, mutants.
Sounds like a win - win to me.
Also, i think the non-degenerate knife ears also have access to the webway, and they can still spin wraithbone as opposed to the Drukhari.
It would be an interesting experiment to raise one inside a sealed wraithbone structure as well, given that it is really good at keeping the daemons out.
Yeah, maybe Girlyman can get his new girlfriend to make her underlings build some wraithbone structures for the Imperium.