OK thats better
I am focussing in your statement that the track is bumpy. If that is the case then try...
1. I am not familiar with HPI springs but if you have used 500 cst to match the springs then I think your are sprung way too hard for a bumpy track. Depending on how bumpy it is at various points this could be causing your understeer on entry and oversteer when you apply the power on exit. If you have the kit XRAY springs also, 2.8 front 2.6 rear, fit them and change to 350cst
2. I have not used prodive but I have used prosquat, very recently, to hold the rear on exit. It certainly improved the grip but made the whole ride very bumpy so I removed it.Our track is bumpy and I suspect (but don't know) that one might only want to use prosquat/dive on a smooth track. Maybe your track is smooth and using prodive/squat is making it seem bumpy
Go back to kit setup
3. Your ride height for a bumpy track is probaly a bit low and you may well be bottoming out. I would try another 0.5mm front and back.
Having increased your ride height, slide your ride height guage slowly under the chassis, from the rear pointing down the centre line until the rear wheels JUST leave the surface. If the increase in ride height, ie your uplift, is 2.5 or more then for the moment you have enough uplift/droop. Do the same for the front.
If you are reading less than 2,5 reset your downstops 0.5mm ie 4.5 and 3.5 - a couple of playing cards are about 0.5mm, put the guage on top of those and set to 4.0 and 3.0
4. More droop helps on a bumpy track. Do away with the cards and change set to 4.0 and 3.0
Make one change at a time and see what happens. If it does not make it worse leave the change on and go to the next one. Don't dismiss them immediately.They will change the handling of the car and you need to adapt to that first before assessing whether it has made it better or worse - especially I think with number 1 above. You will compensating ,most probably, for some poor handling so you need to un-compensate first!
I think I would be inclined to make the changes in the sequence 3,1,2,4
Report back
OOh foam spec car. When you swapped the chassis and top deck over did you put all the screws back as per the foam spec setup? I am thinking that with the springing also you probably have a very stiff car, which for a dusty bumpy asphalt track you don't want. Set the chassis plate to the EU spec screw settings and if the EU kit setup has any stiffenning screws in the top deck (I can't remember), probably at the front if it does, take them out. Err do that before no.3