Wut? Unless you think that real humans really do in fact have latent warp powers, then everyone on real earth is a blank. People don't irrationally hate you because they are also blanks like everyone else. Normal real human =/= normal 40k human. You wouldn't magically change from one to the other if you were transported there. There are no warp souls in this universe, so if you went to 40k land, you would be a person without a soul and a bunch of creepy hive mind "humans" would hate you for not being part of the hive.
No, simply because
you do not need to be a blank to not have psychic power. Regular humans in Wh40k do not have any real resemblance of psychic power, they just are regular folks, but they have the basic soul and connection to the warp that is generated by being simply a living being, that literally doesn't manifest in any way under most circumstances. It's the blanks AND psykers that are different from regular humans. If you somehow went into 40k land, then automatically WH40k history IS real, which means that you do have soul and a connection to warp, UNLESS you happen to be a blank anyway. I am not saying that current humans are actually WH40k humans, but if you assume that 40k is real, then, unless some freak alternate universe where everyone on Earth is blank is involved, you do have a soul, you have connection to warp and wouldn't be anything out of ordinary for hivers, although you'd probably be hated anyway because you'd probably be dressed in exotic way, and in general looked too good, which must mean you're a noble scum that got lost in the hive, and they would promptly murder you for your shoes.
Also, you're mistaking humans for Tau, we do not have a hive mind. :V