Bashan Storm 250 Kill Switch, Exhaust & Throttle

[CaesarVis]

The Bashan Storm 250 does not have a kill switch/stop button on it. The only way to stop the bike is to turn the ignition off. It's kind of annoying. I was wondering if there's a way to add a kill switch, or even better, to change the hazard/flashers switch into an on/off switch. Below is a picture of the starter and hazard switch.

Second, I just installed the typical, cheap eBay exhaust (picture below) on my bike and it's just a little too loud. I know Cravin01 on here installed it and hated how loud it was. Idle sounds amazing but it quickly gets too loud when accelerating. Does anyone have an easy/cheap recommendation for how to quiet it up a bit? Also, was a gasket or something supposed to go between the cylinder head and new exhaust? There was nothing there when I removed the old one.

Third, the throttle on here is super chintzy and flimsy. Can someone please recommend a good, cheap replacement? Bonus points if it's on Amazon Prime and has better grips. I have absolutely no idea what is involved with making sure the throttle assembly and cable work.

Oh yeah, and one other thing I was wondering. I know a lot of people shave their heads by about 0.04"/1mm for performance and I'm considering doing the same. I was just wondering if anyone makes a performance piston that is 1mm taller than stock. Wouldn't that accomplish the same thing and be a whole lot cheaper and easier?