I'm not going to this concert, but I'll answer anyway:

I totally agree with you on the moshing thing. Some people are a bit small and would be easily hurt, and ending up with broken bones and bashed heads is a bit of a fun killer. I'd probably be injured in a heartbeat.

I saw HYDE at Slim's and, thankfully, there was no moshing. But there WAS pushing towards the front as soon as he came out. As soon as he hit the stage the whole room compressed forward so I was literally stuck to the person in front of me. (At the end of the concert, because of all the sweat and stuff, I had to peel myself off the guy in front of me. It was gross).

When you're in the crowd it is very very very hot. So much body heat, so wear something light so you can keep cool. I heard there were people passing out from the heat.

Wear comfortable shoes because you're going to get stepped on. In fact, I didn't even know where my feet were. They certainly weren't under me! And because of all the pushing, we swayed side to side a couple of times and my feet actually came off the ground. I was being held up by all the bodies smashed around me. That's how tightly packed everyone was.

As for behavior, it varies. Some people are friendly, some people become bitches as soon as the concert starts. I was mostly okay, but my sister got stepped on by some girl's mother on purpose so that her daughter could move forward. I think my sister said she ended up on the ground and someone had to help drag her out, but I don't quite remember. She moved to the back after that, though.

I didn't really have any issues with anyone, personally. The only iffyness with me was that my arm was stuck around some guys waist (I had been holding hands with my sister, we got separated, and the moving crowd caused me to end up with my arm around the guy in front of me's waist). Toward the end of the concert I guess his girlfriend got sick of my arm there, and she shoved me off. That was the only issue I had.

Some other people had horror stories though, of almost getting into fights because of others trying to violently shove to the front. There was some issues with Japanese fans injuring others to get to the front (spiked heels, or something), but hopefully we won't have that issue this time.

So basically it's 50/50. Some people will be nice, some people will be out for your blood.

If you do make it to the front, you're going to be smooshed like crazy because everyone pushes forward. So you'll be smashed up against the railing.

And after the concert, if you linger around you might get something off the stage if the techy guys throw some stuff. One girl I was talking to nearly got hit in the head when a drum stick was thrown out. Sadly, someone else got it before she could grab it.

Try not to bring anything breakable, because if it hits the floor it's gone. The girl next to be dropped her glasses and at the end of the concert we found them on the other side of the room, smashed.

Sorry for the long reply, but I wanted to make sure I mentioned everything so you'd have an idea of what to expect.