cost:
i just paid for my 2009 model insurance and roadtax.
cost me 2.2k (300 plus for roadtax rest of insurance).

performance:
stock 1.8 you will definitely feel you're driving a more powerful and stable car.
your city i know is capable of going 140-150km/h
civic can do that without breaking a sweat and without the wind noise and feels alot more stable.

fuel consumption:
where your city has good pickup and good fuel consumption for town driving and traffic jams.
civic won't be like that.
you won't get the 500km plus per tank you're used to getting from your honda city.
you'd still get upper 450km per tank which is quite good considering the extra horsepower you're getting.

parts:
i suggest you get oem parts since the car is warranty over.
the cost will be much more bearable, however it will cost you abit more than the city.

if you're traffic outstation you'd get 550 or abit more from the civic, depends on how you "speed" .

i can't really tell anymore since i've put in 18" rims all the calculations kaput liao

190km/h in city i've tried that before from johor to kl.
takes a long time to get 190km/h.
i've done 206km/h on civic even without notice it while driving from cyberjaya to klia. u don't need a long straight to go 180km/h with civic, u need for city

Other than the current Steering issue, look also for rear wheel bearing issue, Hydraulic mounting & also chipping brake pads