Newbie to this, but is this a normal sound?

So, I had a bit of an accident and fell off my scooter at about 15mph. I'm fine, but now I'm a little worried that there may be something wrong with my scooter.
There is a high pitched rattling sound, like pebbles in a place where they shouldn't be (Possible considering where i came off) when you rev the engine.
It's a Lexmoto milano 125 EFI, and it didn't make this noise before (I think)
Here is a link to the audio file on my site where I record the sound for you to listen to.
I'll be able to answer any questions you have about what might be the issue.
I have checked the cowling and fan, that's all fine.
I also noticed while working on it yesterday, that the rear brake disc seems off-balance, and the rattling seems to be coming from it although i can't be sure. Could this be it?
Here is a link to the video I took of it, on my own server.

Thanks all!

EDIT:
The scooter also feels less stable after the accident!
ANOTHER EDIT:
Yeah, this isn't normal. What could've gone wrong?

 

It could be the exhaust. Or exhaust guard thing. (The chrome cover)
It's pretty common for baffles to come loose inside the exhaust. I've seen it across all brands pretty much...

 

No damage to the frame or exhaust. I honestly think it’s the brake disc or the piece which holds it in place. It isn’t loose, but it just seems.. off

 

Original video:
https://redfoxit.co/mp4/brakedisc.mp4
New vid of inspection:
https://redfoxit.co/mp4/inspection.mp4

The thing is, now it's making the sound less, but vibrating and that brake disc doesn't look right at all...

 

You know, the entire disc seems to be off. It’s not wobbling side to side, but up and down if that makes sense. I think it came out of the factory like that and I just haven’t noticed. It is a £1,600 scooter after all. And also, taking the wheel off to take the disc off seems above my skill level. In my Haynes manual it shows a different assembly with the gearbox and brake on the same side, but on the Milano, they are on either side. I’m just gonna use it and see if it works okay. The noise seems to be going away now (likely some pebbles somewhere they shouldn’t be) and it doesn’t run bad so I’m going to just keep using it, and if something happens I’ll come back to it. A disc is only £20 to replace after all.

 

I can yes, but I think that rebuilding the rear is above my pay grade.
If it were like it is in the Haynes Manual I could.
I have rode it since and it seems okay, and the braking feels normal you see. The rattling seems to be going away (Little rocks keep spitting out of places, and I think that's the issue.)
I honestly thing it's just because Chinese scooters aren't made to the same manufacturing tolerances.
What do you think?

 

Actually, you may think that stripping out the rear end is above your pay grade, but it isn't.
It's only because you haven't done it before, and that's what makes it daunting.
The Haynes manual will give you a good guide, but not everything, as it is a rather generic manual to "most" chinese scooters.
On anything new to you, it is a good idea to take plenty of photos as you go along, that way when you come to put it back together again you have a reference point.
The main point is do you have the tools to do the job in the first place?
If yes, great, get stuck in, it's a great way to learn.
If no, then leave it alone and take it to someone who does know.
If you have half a brain you will notice that something doesn't look right, and if you're not sure, most of us are here to help as we visit the site.
Just don't expect instant replies to any of your questions please, we're all busy with stuff......

 

I get it, I really do.
But the noise has disappeared (Little rocks flew out of somewhere) and it rides like normal again after pumping up the tires....
I don't know if the wobbly disc brake was there before, but I suppose if it is broken, it's only a £20 part.
The thing is, with the gearbox and the brakes being on either side, so it's all rather complicated. (To mea at least) The only other thing is that the nut holding my wheel on is slightly too big for any of the tools in my socket set, so without buying another tool, I don't have a way of getting the wheel off.
Is it possible that the disc can be changed without taking the wheel off?
If so, then if any of you are confident that I can get the exhaust pipe off, then i'll do it and take pics.

Thanks for all of your patience.