If you want to replace plastics with alloy parts, you'll be adding weight to the car. Where you replace steel with aluminum, you save weight. So, if you seriously want to go faster, you'll eventually have to keep the amount of plastic being replaced by aluminum to a minimum and replace steel with aluminum wherever possible.
TRF shocks and alloy suspension blocks will help with tuning and overall suspension smoothness. I wouldn't say that the stabilizers are absolutely needed; they are nice to have in many cases though.
The woven type of carbon parts will reduce weight and have increased rigidity over the stock plastic parts, but they are not as strong as aluminum parts. The injected carbon parts are stiffer, but not lighter than the stock TA05 plastic, except in the case with the LW chassis because it has extra cut-outs in the structure.
Alloy turnbuckles are far weaker than the stock steel ones or Ti. I prefer to use Ti for turnbuckles and screws because of its compromise between the strength of steel and the light weight of aluminum.
Steel front universals and aluminum-shaft rear universals will improve the strength of your drive train.