I recently added a male blue ram to my community tank ( 46gal. with small tetras, barbs, corys) and it is quite docile. I would like to add more but I am unsure about creating aggression.
If I get another male, will they quarrel ?
If I get a female, will they be agressive towards other fish ? I understand they may become agressive when spawning.... or will they not spawn in a populated tank?

Thanks for you help

46G is plenty big for two males to set up their own territories IMO. You may want to mix up the decorations and do a water change when you introduce the second one as it will give both an equal opportunity to claim their own territory. If you get a female and they do court, then they will be protective of the ggs but not super aggressive. If any fish comes near the ggs or wigglers, then yes, the ram will lash out, but only out defense and will not purposfully pursue the fish just to hurt them. But, there is a good probability that even if you get a female, they will not pair as usually it is recommended to purchase atleast 6 members of a species and let them pair off naturally, returning the remaining four once a pair has formed.