How can I use a tripod with a camera that has no tripod mount?
Well, that tip is exactly what you considered but already dismissed anyway: Another idea could be gluing on a nut to the bottom of the camera. The disadvantage would be that the camera might no longer fit into its case which also serves as the only means of covering the lens. Plus, even if it fits in the case, I wouldn’t trust that it wouldn’t get knocked loose at some point. Loose enough to not notice until it fell off the tripod. Might make a final interesting last photo though: a blurry image of you with an “OH CRAP” look on your face.