There is you problem, you owned a ForTwo, not a roadster!
The servicing on the roadster is every 7,000 miles and the oil required is Mobil 1 or a very good 0-40W fully synth. They have 6 plugs to change and the rear of the car has to come off to change the bottom 3 plugs. They are cheap on fuel, but not cheap to run.
They are not fast cars, what 699cc car is?
Re the gearchange, in Auto it is very poor, but then so is the Toyota MMT, the Citroen Sensonic and the Honda i - Shift. When specced with the steering wheel mounted paddles, the gearchanges takes less than a 1/4 second when properly set up.
I wouldn't want one as a daily driver though, unless every day was sunny and you can take the roof off!