I don't know whether it's possible to have more than one weapon but I know you can lay traps.
If indeed it's one weapon per person (per hunt of course), my guess is that's where having a hunting party is a major advantage, each one has his own weapon with different advantages/characteristics and different shielding, each potentially complementing the other.
Currently Playing: Shin Megami Tensei: Devil Survivor Overclocked, Professor Layton and the Curious Village
Anticipating: Xenoblade, The Last Story, Mario Kart 7, Rayman Origins, Zelda SS, Crush3D, Tales of the Abyss 3DS, MGS:Snake Eater 3DS, RE:Revelations, Time Travellers, Professor Layton vs. Ace Attorney, Luigi's Mansion 2, MH TriG, DQ Monsters, Heroes of Ruin