welcome to the forum, well where do I start, I am a petrol/diesel head tweaker and mod minded ie I like to get that little bit more. But after 4 months ownership of our dooper I wouldnt mod it further, I have a DTUK box in it, but if you have the flat spot good luck in sorting it, its such a pain. Do a wee search on the flat spot, my next fix is changing the crankcase sensor to sort it hopefully.
Happy Modding ;-)
Oh and the thought of leaving a cooper s in smoke, I do it already in my Abarth 500 esseesse. ;-)