You'd need to fill the outer teeth on the stunt to make it hero as well. Not just leave them untrimmed. Best one the market is made by TM, if you're looking to buy a proper hero helmet.
Or at least appear hand painted. We do approve "hand painted look" decals. So if you want to airbrush your details, they need to emulate the sloppyness. (To some degree.The painters of the real helmets were very skilled).
It should be obvious that any measurements are derived from screen accurate measurements. That being said, gov. issue rarely takes consideration to size of whom it's issued to. so if the empire makes 3" belts they should be issued to everyone. Just like in the real world.
In that case you should not get a hasbro since they take quite a lot of work to modify to get any decent results, even with the conversion kits. If you're in the US I'd recommend saving up for a hyperfirm once you've decided which version of TK to build.
Blasters are optional and GML's can't decide on approval or not for not having the right kind of blaster. But technically the conversion kit only makes you an ANH blaster. I would recommend getting a pipe blaster kit instead of a hasbro either way.
If they are good enough, you can use the same pictures. In your case, most likely. But more often the EIB applicant is not up to centurion specs at the time of the EIB photos.
Personally I think the "proportion" argument about the belt is a lame excuse. If you're a big guy, then a 1/2" slimmer belt is the least of your proportional problems. Same thing with small guys (like me) and ladies too btw.
In your case the holster is the least of your problems. If you see what I mean. While you are making excellent progress on modifying your rubies, it will always be a rubies, and no holster will change that.
The straps doesn't have to be longer, but commonly is. Both long and short straps are seen in ROTJ. But they were all black and riveted to the right side of the belt.
The CRL's are all kinds of messed up IMO and not easily changed. There's little we can do but to educate and promote the proper measurements here at FISD.