I like the idea of making something more functional, but I'll stick with making plastic "toy" replicas. 3 out of my 4 items already wouldn't pass to go on a convention floor.
Depends on the con. I've personally seen (and had) 3d printed swords, and con-mates with daggers; they just cant have sharp points, which if I had to assume, they're more dull (for obvious reasons) than sharp. The staff is obviously fine. The only questionable one Id say would be the KKK. Im not sure how they would take that; I guess it depends on how strict that certain gopher/con staff are, for example, I was able to bring in a 2nd sword in to a con one day, but was getting some push back with the same sword the next day and had to get higher approval.
But realistically, I'd say 3/4 would be allowed at most cons.