Yeah that’s the main concern for me …. Broken studs! That’s worst case scenario for meThe one in that clip does appear to be missing some nuts and studs.
Pre-cat fumes can kill you, post-cat just give you more of a headache.
If you can get the heat shield off then it should be clear. Though not sure if the 500 has a cast manifold or not, you can get some pretty subtle cracks in the cast manifolds that leak and change with temperature.
I’m hoping when I get in there none are broken and I get the nuts off without breaking any (doubtful) but that noise is exactly what I get when I rev so it’s leaning towards a leak! If I have any cracks I’ll just have to get in touch with club500 and go from there .. thank you for the info & tips I do really appreciate all the help