I've only seen them in pictures, do they have a shiny type of plastic? That would make them a nightmare to repaint :/
Honestly I don't like them at all personally... But that Rarity rehair!! 

The plastic is the same, or at least similar enough that I didn't notice a difference. The heads look a little shinier in photos but I think that's because they're more bulbous and have sharper angles on the muzzles. Here's a comparison between Twilights:


I haven't tried repainting one yet, but I would assume they can be painted the same as the earlier g4s! If I get a chance maybe I'll do some tests, I have a Fluttershy I'm not super-fond of anyway (got her just because she came with Celestia).

I rehaired one the other day! They're exactly the same inside as the older play-size G4s, with the glued-in neck plug. I think the neckhole is smaller (as if they weren't small enough already) so dehairing was a pain, but otherwise no real difference.

With her head off:


And with her new hair:

Thank you!

Thanks! 
I love your Celestia army! I love that white custom on the blue wood and the figure of tia sitting down. So cute! 

Thanks! The custom on the wood is by Kar Red Roses, I can't remember who did the filly Tia.

Oh wow, she's gorgeous! I love the expression you got out of her!

For the cape, you can cut your fabric on the bias to make it drape even nicer. I think a very sheer fabric or even black lace would look really nice and show off the back sculpting and tail. c:

If you're not afraid to wash it, soak it for a while in white vinegar, just enough to cover it completely. Then run it under cold water. Repeat a couple dozen times (the water should be running completely clear by the time you're done). The vinegar will set the dye into the fabric and greatly reduce, if not eliminate staining.

You can also buy some cheap undyed fabric (like muslin) and wrap strips of it around your pony where the staining is occurring, or line the parts of the outfit with it. That creates a barrier between the plastic and the fabric so the color won't bleed onto the pony itself. c:

It's essentially the same as sending in new ideas for TV shows or movies. They send pretty much the same letter to everyone who submits an idea because they'd be positively inundated with ideas every single day if they didn't.

Well, it's not really about the number of submissions as it is that when it comes to intellectual property (in the US at least), it can turn into a whole legal can of worms to so much as acknowledge being aware of an idea. Most companies like Hasbro will only deal with in-house employees or approved agents/brokers because that way they know that the legalities are being handled in a way that won't potentially land them in hot water somewhere down the road. Unsolicited submissions, sadly, have to be ignored.

Most likely they saw the subject line and fired off a standard stock-reply, which is probably why it doesn't seem to quite match up with what's being asked (which seems to be more about brand licensing for a video game than an actual product pitch?). Either way, the talk of brokers is just a suggestion on how to pitch through the proper channels; it definitely isn't granting permission to use their brands in further pitches. Sorry!

I'm not sure about curl-styling, but the tinsel-straightening method for older gens works pretty well for the Shine Bright G4s too! Take hold of a strand of tinsel and pull on it GENTLY -- not hard enough to pull it out! -- you should feel it kind of stretch a little, and then it will lay flat. Makes it MUCH more manageable!