Another left hander here. The only thing I do right handed is play the pipes. Actually that way of holding the pipes seemed most natural to me when I first started anyway. I guess maybe they're a left handed instrument by design. Also a reenactor/rendezvouser. I have a Dutch trade musket that I shoot right handed. It's a bit puzzling, but I tend to do better than I do when I try it left handed.
As far as kilts go, no problems at all with modern style kilts, or even the old style fileadh beagh. When I wear a great kilt at an event I usually wrap it opposite of what a righthander would, and draw the plaid over my right shoulder, since that would leave my sword arm free. Most folks who even notice the difference figure I wear the plaid on that side because of the pipes. I've noticed the drones do sit on the shoulder better without the plaid under them.