Hi there,
1) The 3rd brake lamp indeed 1156 socket was reversed across all GaGa every since 2008, from your local S16 until now FLX+. You can simply unfold the LED module and reverse the input, and or rewire the socket. HOWEVER! Here comes the problem, 1 of the function in the engine management is to detect voltage abnormal on light bulb's output

Once you change the socket layout, plot the LED module, it works like a charm and you praise that yourself as a genius, then the CHECK ENGINE indicator(CEL) lite up on your dash because the ECU sense voltage utilization on the 3rd brake light utilize much less current

In order to counter this, our friend
lhwj &
coolkwc had wired up a resistor to the 3rd brake lamp module and managed to cheat the ECU on a regular voltage usage on the 3rd brake lamp.
2) Yes the turn signal lamps are wired reversed. Simply change it back and you'll be able to use LED. The signal blink relay can be exchanged to a common LED use. But the blinking speed will be slower.
Fuel consumption wise, the Campro S4PH is a known fuel monster. However, the CVT is there to help up. Know the wet clutch engagement timing is important as the clutch engagement trigger is the brake pedal. Usually from a standstill, after release your foot from the brake pedal, it take some 1/2 ~ 1seconds until the clutch fully engaged on the flywheel. During/before the engagement time, stepping on the gas pedal is what a Chinese old saying goes "waste gas". If unfamiliar, after release brake pedal, wait for the car to start creeping forward, then gradually increase gas pedal.
By nature, the tall Campro engine is made for high PRM torque. Hence, within 1000~4000rpm is the weakest point of the torque output. Plotong utilize an Air Fuel Module(multiple intake runner) to lengthen the intake runner on lower rpm. Keeping your RPM within 2500rpm range will reduced a lot of unwanted fuel wastage(naturally the IAFM will try to pickup more air/fuel to the engine to counter the low torque within 1000~4000rpm).
Log your fuel ups in
http://www.fuelly.com/ to track your petrol consumption. You'll be able to compare your fuel consumption against others, to see whether is there any problem with the car or your right foot

Thanks for the info, I ended up swapping the wires in the plug, it rained yesterday so any job was too hard but I found my long spiky thing and eased out the terminals and swapped them over. The 3rd brake light now works fine and thus far hasn't thrown a CEL, but bear in mind the flx already has LED brake/tail lights so that issue might already be addressed. I'm not a fan of using load resistors, it sort of defeats the purpose of using LED.
Interesting about the clutch operation on the CVT, I'll do more driving to become familiar but I'm usually a sedate driver which seemingly is well suited to a CVT, I certainly don't expect to break a crankshaft near the rear main bearing.
edit: Predictably when I took Daisy for a drive the warning lamp came on, bugger. What was fancy programming a decade ago has now become a nuisance for those of us who wish to use lights made in this century.