For No. 5
Bullets can be fired outside of the barrel, you need to be able to crimp the rim in the same way that the firing pin would have done against the chamber. Unlikely that you could do this by just holding the bullet, brass is too hard, you would need to hold it against a solid surface.
What you can do though, is pinch the rim in a pair of needle nose pliers (ones with wire cutters at the pivot work well) gently first to hold it steady, then squeeze hard and fast to crush the primer. I wouldn't recommend doing this with the lead part still attached as it will provide enough resistance for the brass (and lead itself) to fly off in random directions pretty fast. You can use the pliers to twist off the lead part first, then go ahead, it just makes a bang and a puff of smoke like a blank.
Source? I used to do this with misfired .22 rounds at the summer camp I worked at - misfired ammunition couldn't be thrown in the trash so I would take them apart. Usually (because it was cheap ammo) the firing pin had knocked the primer out of the rim instead of crushing it, in which case I'd just collect the powder grains for fun later on

but sometimes the primer was still there too, just hadn't worked the first time, all sorts of experiments done on these
You can hold a flame under them too, this made a much louder bang than crimping the rim for some reason, I never figured out why...