Get some "red rubber grease" for the welnuts, don't use copper grease (it destroys them).
Uprated clutch slave cylinder is a good idea - Nelly does them, I had one from Tecmoto on mine. That was a slave for a 916, so I am guessing that the ones Nelly has will fit the ST as well.
Cornerspeed Might want to think about modifiying the bit of side fairing that gets trapped under the nosecone - it's well over engineered and it means you have to take the nosecone off to get the side off (if I remember rightly).
If you find you need any parts I still have a load in the shed ... not got round to getting them on ebay yet.