This is going to be a good thread to follow and share ideas. Thanks Tyvern, for starting it.
I can say from experience that Rare Earth magnets is the best way to go. I'm using the Rare Earth magnets from defective Hard Drives.
I'm currently using 8 of them to hold the front of my chest piece together.
Ventru is correct about the shearing forces. For that I've modified 2 Parachute clips to keep the chest piece from sliding/shearing. --AND-- When I split my Torso piece, I did not cut it in a straight line, I cut it with a zig zag type pattern. So far it has worked out PERFECTLY.
I plan on adding magnets to the Thighs, Back, Belt pouch and Hand Plates.
Cheers.