Exactly what the doc and Lowtar' said
AsFor the strongest bond try to glue metal to metal otherwise the bond will only be as strong as the bond between paint and metal, which isn't great.
When attaching bare metal to base metal clean the figure area first there may be some release/casting residue on the hand, meths on a paintbrush will work (and it flashes off). Also if you can get a flat surface and "roll" the metal spear with a file you'll rough the surface of the spear up. This will provide a tooth for the glue. I recommeded Loctite superglue! Pretty sure ounce for ounce it costs more than gold but it is strong. Epoxy will give a good bond but as Andrew said it shows a noticable blob if not applied thinly, but then really only works best with a thick layer.
Crimping the hands won't flatten too much of the detail if you protect the figure. When bending/repositioning figure parts I protect the area with a thick rubber band before crimping, a wad of tissue works as well. You can put enough pressure on without ruining the detail. Good way to reposition a head without flattening the ears!
Another tip... if you have the time pare away at the inside of the hand with a scalpel which will both clean the metal for gluing and thin the hand so once glued and crimped the result will look more realistic.
As to transportation I'd advise some sort of magnetic basing. This'll keep the figures from bashing about. Those foam cases which squash the figures between to pieces of foam won't help. Heavy duty ziplock baggies can be a great solution although for large amounts of figures they can be time consuming to put in/take out.