I would definitely get rid of the stock rtr shock fluid. It's not the genuine losi bottled stuff it's some nasty stinky oil.
Another thing you might have overlooked is ride height. The losi's are very sensitive to ride height changes. The truggy should be set at this:
Front- 36mm
Rear- 38mm
Try this as it's the base T 1.0 race roller shock setup and it works excellent.
Shock oils:
Front- 54 piston/45wt oil Black spring
Rear- 56 piston/30wt oil Grey spring