Laugh at me

as far as going full int nuker
my question would be
nuke with what magic ? or are we just talking about the forces we can use with our weapons ? also most of the guides say use a bow until level 30 then switch to sword and sheild well why level bow skills then ? or am i supposed to be leveling up sword mastery or what. Explain thx
cause ive read all the guides and crap and non of them explain that but all of them do say that at level 30 you will level alot faster and farm better by nuking.