The crossbelt is pretty "costumey" unless you are in uniform with a pipe band or military unit. The only real reason for a baldric is to carry the weight of a sword . . .or a drum. Or to make a uniform look cool. I fear that any other use of a crossbelt would cause you to appear to be in costume rather than simply wearing highland attire.

Having said that, you might have occassion to attend a Ren Fest somewhere and dress as a highland gentleman of old. Or--if you are really bold and want to stand out--you might even attend a very dressy occassion, don your best doublet and swing the sword over your shoulder while wearing a dirk and maybe even a pistol and powder horn to show your sense of style. I would like to do that, personally, but I wouldn't actually do it; too "costumey" once again. You'd have to know your friends well and be assure that it was appropriate so as not to look like some goob!

But be prepared for ridicule or even laughter if you do unless you are with a group that normally dresses in such fashion.

Finally, you might wear it to the local highland games if you so desire. I've seen people wearing much stranger things than a crossbelt, so I doubt anyone would say anything. Just know that you would be considered to be in costume.

As to swinging the sword from the baldric, you may need to adjust the frog at the bottom to fit your scabbard. There are brads and leather working items just for such things at the local hobby store. The rings on the scabbard are to attach to a sword belt, the kind with the long strap in the back which attaches to the lower ring to make the sword hang properly. (You've seen such in old cavalry movies, but rarely with the sword actually attached.) I would focus on fastening the scabbarb tightly in the bottom of the belt. See this site that shows the method of fastening. http://budk.com/Swords/United-Cutler...-Sword-Harness