[KarmaInferno]

Do throwing weapons (currently throwing stars, knives, and a chakram) get weapon mod slots as "throwing weapons" (meaning zero as it's not a listed mod slot category), or as "blades" (as they're all edged weapons and use the Blades skill in melee)?

[Hobbes]

Two would be my guess.  Blades and Clubs are two, so three or more seems highly unlikely.  None is silly.  Leaves us with one or two, and two seems more likely.