I disagree with you there, as long as it's marketted the right way.
The name "Riflemen" is more an homage to Canada's military history than any glorification of weapons or killing. The Ottawa Riflemen would no more promote violence than does Rememberence Day. Even though it could be said that our military has been neglected over the years, I think Canadians still have a soft spot for their military history, and this would be enough to overcome any misinformed objections.
According to Wikipedia, the Bullets' name change was the decision of the owner, not the result of public outcry:
In 1995, owner Abe Pollin announced that the franchise was to be renamed because Bullets carried violent overtones, which he wanted to repudiate, especially since Washington was experiencing some of the highest homicide rates in the country at the time.
Besides, Ottawa doesn't have quite the level of gun violence as does Washington DC.
Borrowing from military tradition gives the team the chance at having traditions right out of the gate, something expansion teams typically lack. I'm thinking blown up vintage photos of WWI/WWII era Canadian soldiers around the stadium, the football teams that formed in the military during wartime, and of course, the old Ottawa Rough Riders. I've read on the internet that the Cameron Highlanders (as the old Ottawa and Carleton Rifles are knows today) have an impressive military band, complete with highland regalia and bagpipes. Imagine the atmosphere in a 30k seat stadium when pipers welcome the team out onto the field or celebrate a touchdown.
Finally, given the highland tradition of the Camerons, I think the team should sell kilts in the team colours. Just something I think the fans at the games would enjoy and contribute to a rowdy atmosphere... oh, and don't forget to put kilts on the cheerleaders as well