The thing that snapped is the right side fork protector. Try a dealer, or an online parts store. By the looks of it, you've got stickers on them, that won't come on the stock part, or an aftermarket replacement, so you'll have to deal with that if you're worried about them matching.
The pipe/silencer joint may be worn and loose, or there may be something missing from the joint, like a rubber sleeve to help seal it. If you go to Yamaha's website, they have the parts microfiche on there, and you can check to see if it all is present or if something is missing.
To seal the pipe at the cylinder, get a new set of O-rings and springs.
Your jetting may also be off, which will increase the spooging.
About all you can do to stop the rust is clean it up and put on something like that to prevent it. When you are in a humid climate, the moisture in the air tends to rust exposed steel and iron. Replace any severely damaged fasteners, with new ones.