1) While it's a bad pun, I do admire the cleverness in it. There's just not that much funny about toy soldiers (toy soldier collectors - now THAT'S funny!).
2) For repairs, it depends on the composition of the figure. For some figures it can be also as easy to make a new bayonet and glue it on as a full part. For arms, heads etc, either when customizing plastics, or repairing others, I prefer to "pin and glue". I get the trustry Dremel drill and make a hole in each part, I then insert a short piece of brass wire. Then when I glue the parts together the wire inside adds strength and alignment. Five-minute epoxy is messy but seems about the strongest adhesive readily available to me. Usually I use ACC ("super glue") on most projects and small repairs. Just be sure to clean up any extra cement, first to not have a glob showing and second, to avoid the whitish residue often found with cured ACC.
I touch up paint "by eye" using good old trial and error.
As far as a glue gun, my wife uses one on crafts and our sticks keep leaving "strings" of glue that need to be cleaned up. Further, the craft glues don't seem particularly strong. Maybe there are better, stronger glue sticks out there. A hot glue gun CAN be very useful for attaching scenery, trees, etc to a base, especially if your using styrofoam.
Just a few thoughts from an old model builder.