I would compare the costs before I gave a definite yes or no. Hanging in a window will soon become sun damaged and faded. It might make more sense to purchase an actual flag and replace as needed.

I have never found a need to use stabilizer, but if I did, I would use the WSS (the clear film) or a washaway paper and dip the flag in water after finishing. The seams in nylon are delicate (to some extent) and I'd be wary of tearing away stabilizer for fear of pulling seams apart. Just my fear. My flags sometimes hang outside in all weather for 2 or 3 months--just because I can't think of an appropriate replacement (or because I procrastinate!). I still have flags made before 1998. Okay. I need to do a clean-out! Some are getting very faded.

Google 'Canadian flag' and see how much a premade one costs. Does this person think fabric is still 39cents a yard? I think that one bought already made would be less expensive or close...and without all the work. Do what you enjoy, not what others expect you to do. JMO