You know what I want to say, so I am not going to say it! (Re the carb rebuild.)
But I have to confess that now you have got it running, if I were you I'd get to the bottom of the smell of petrol because I seriously don't think that is a carb problem. Especially as it is behaving as if it is running weak. If the jet needle was stuck down it would be coughing and spitting and excess petrol would be coming out somewhere, can't remember on HIFs, where but on SUs previous to HIFs there was a little hole at the top of the float chamber. Standard needle is BDL although I appreciate it has been skimmed.
I hope it sorts it out to an extent.
But you are totally right that you cannot tune a car properly unless you only work on one variable at a time.
It doesn't mean that you won't revisit each one again, but setting each one to its basic position gives you the chance to then fiddle with each one seeing what improves it.
(I'd also have started with the tappets but then you may well have done that. )

Best of luck, you sure as heck cannot make it any worse!!!

