The driving technique used and how it differs between a RWD and FWD platform will only ever be able to marginally mask underlying fundamental deficiencies with the FWD layout.
You are correct in saying that this is not Formula 1 we are talking about, however, It is on even amateur level racing and racetracks that the FWD starts to drastically lose ground to it's rear wheel drive and (4WD/AWD) counterparts.
As for the torque steer issue, I see it as another negative aspect of the FWD handling dynamics, however, it is not central to our issue at the moment.
The main point I was trying to make is that although FWD platforms may be able to be engineered to perform at a certain level, as you are still requiring the same two wheels to provide both propulsion and steering, something which drastically reduces the ability of the tyres contact patch to do efficiently, this means that a FWD layout will never perform as well as some of the other platform available.
You may be able to mask these detrimental conditions with some of the measures you have mentioned, such as LSD's and ARB's however, all of these solutions are those which may also be applied to the RWD and AWD/4WD platform meaning that all three systems have fairly similar levels of tune-ability however with front wheel drive you are simply starting from a less efficient platform in my opinion.
As for the tuning of the handling characteristics, inherent oversteer/understeer this may be adressed and changed dependant on the various requirements of the driver and are not mutually exclusive to any one drive platform.
Cheers,
Mitch.