Answers of your questions one by one
1. It doesn't require frequent replacement of parts apart from air filter,oil filter, ac filter.
2,3.4 Parts are easily available not that much expensive eg new water body costs 2400, kabuli power steering pump 2000,2500 USe ngk spark plugs specifically for civic. Parts are available at bilal ganj.
5. I don't frequently clean the engine bay never washed it with petrol or direct water. I just get it cleaned with air and sometimes I use degreasers.
6.easily available at almost every car decoration or parts shop better buy kabuli genuine. I never bought them though as mine are still original.
7.I bought a clutch plate for around 5k and pads for 2k of nissin brand.
8. I don't use any
9. Its highly recommended that you flush the radiator and use caltex coolant in 50 50 ratio. One litre costs around 900. Buy three. Check pipes ,thermostat radiator for leaks. You will not need to top off the radiator again for at least a year or two.
For appearance I only used formula one wax polish and shampoo, glint for windows, luster like sprays for plastic parts. Dirt and grim remover for rims. Paint is still all genuine it didn't fade. I never used compound on it and never got it serviced at a pump.