that is so cool about your S.O mine supports my faith but i would never see him using a protective or blessing spell if he were given one. i like the idea about the mini altar and the exacto blade, i often wondered about what you would use as a 'mini athame.' althought in my town they are really strict about anything that could be classed as a weapon so i dont know i i could get away with it.
I've used a large needle before to substitute as an athame, and I don't think you would get in trouble for having that. A letter opener is a good idea too. I had a friend who used a piece of ceramic with leather wrapped aroun the base, it wasn't sharp or anything. If you could make a small one of those it could work. I know that there are sword and knife shaped charms to go on jewelry, but finding one might be difficult.
Now thinking about it I suppose it would be easy to repurpose a small sewing kit, like they sell at gas stations into a mini alter. the thimble could be a cauldron, the needle the athame, so on and so forth. There would also be thread for tying together herbs, or for spells useing knots.