I am confused about the product(s) of NBS/CCl4 reactions. When you react trans-2-pentene with NBS/CCl4, it says the products should be trans-4-bromopent-2-ene and cis-4-bromopent-2-ene. Why wouldn't you also get 1-bromopent-2ene and 3-bromopent-1-ene? It seems to me that the resonance forms of the cations would account for those two structures as well. Also, why would the structure invert to a cis formation? The bromination occurs at an achiral carbon, doesn't it? It does not involve the double bond at all.
Also, I do not understand why reacting methylbenzene with NBS/CCl4 would yield only (bromomethyl)-benzene. Wouldn't the reonance-stabilized + charge delocalized across the benzene ring also account for the following other two structures below: