Emmet is right, the grey fabric on the toebox seems to be stretched by the rigid toe piece when they've done it in the factory over the shoe last.
I don't know what its called or what type of material it is, but i've removed it on a few pairs straight after cutting up the toebox, and you can see that is quite hard and stiff.
Sometimes it peels straight off in one piece, while other times, it seems to be stuck quite strongly to the inner bit of the grey fabric.
When I put a hairdryer to it, it sort of melts and goes very soft and gooey like a glue or something similar. You can even start to peel it off then or scrape it off, so I believe steaming with the iron is doing the same thing, its melting it and then you are reshaping it down.
I got two of my own pairs which i've done the toe modification on (cutting them up and glueing back) and since they had slight creases, I simply put my hand or some fabric inside the shoe, got a thin towel and started to iron over the toebox.
All the creases have gone and the toebox is now perfectly shaped. I even pressed down on it, and it just pops back up perfectly.
I'll be getting some more fresh pairs to modify shortly, so I will do a test on them, but I think the steam iron method should work and save you from having to cut up the front.
I'll try it on some fresh pairs and see if I get the same results.
I too am curious how the ironing of the toe mod will hold up. I just can't see this fabric shrinking. Even with my toe mods, after removing quite a bit of fabric, the toe tends to get pushed up a little. We shall see. I would LOVE it if this is a true may to do the toe mod but I am skeptical of it's long term permanency.
as for the black silicon, I guess you could do that. the clear shows up in photos much more than it does in real life, so I am not concerned about it, but go ahead and try it. As for the yellow NIKE emblem, I used yellow EL and put the clear/black NIKE logo over the top. It's the same NIKE logo that has been posted many many many times before.