Some printing programs allow you to print a poster size, you could print on the fabric sheets if you have an ink jet printer. I'd try it on regular paper first since the fabric paper is so expensive now. In my avatar I did two ships on
the photo fabric sheets. Yes you can applique photos, you put the fusible on the back side of photo just like regular applique. If you do the fusible on a poster size tho it will make your photo stiff...there is a way to do just the edges so it stays soft but I can't remember how thats done..maybe someone else will help with that or you can search. good luck with your project