Regarding the exhaust stud nuts. When you get the nuts off, and replace any studs if necessary, use stainless nuts rather than the oe ones, using copperslip. These will be a tad thinner leaving an amount of thread exposed. Fit stainless domed nuts on the exposed thread, using copperslip again, to "seal off" the stud. If you cracked these one at a time once a year and re- copperslipped, you shouldn't have any problems.
Whizz kid sitting pretty on his two wheeled stallion.