Katana is just a katana, the guns are just guns, and yes that's a dread's badge.
I don't know what the sword of omens, CS, or H&K are?
It's funny how many people think the katana's and guns are a homage to someone. So many characters who may use a katana or a bunch of guns (without anything special on either )...how could I single one of them out? Personally, I don't see a connection since there's nothing individualized about the weapons
The "gremlin" creature is a Darkling from Image Comics' "The Darkness". The mace on the wall looks like one used by Hawkman. The mask belongs to the titular character from David Mack's series "Kabuki", though the teardrop under right eye is missing. Is the smiley badge supposed to be a reference to Transmetropolitan?