Use bonding web, or iron-on fabric glue, to hold the patch in place. However, since that isn't a permanent solution, you still need to stitch the patch down.
Yes, but it's not really worth it since you will be adding shaving cream. The lotion, shaving cream, and foaming hand wash will make the glue look white, instead of...
Hot glue would not work well for fabric. Fabric glue would work to make the hat without sewing, though the pleats may be a little tricky, and the hat would...
T-shirts are highly customizable. You can have the ends of the patch show outward without being rolled inside by sticking with fabric glue or sewing it, you can roll or...