yes and no. depends what kind of violence. If you are shoving each other around yes but if you are punching each other than no!

Its a contact sport of course there will be the hard tackle but its not violent. You want violence, look up the 1956 Olympics for water polo, Hungary v Russia.

yes

not merely. You can not put that much violent into league but it can still have the same effect in union. I play union for england u21's and in training we play league. There are some fatal injury but it is not violent.