Longer change intervals is about all the benefit there is in a vehicle used under normal conditions.
It is your choice. It can even be mixed with conventional oil.
SAE 5w30 Conventional or Synthetic any major brand.
SAE 5w-30 any major brand conventional or synthetic
SAE 5W-30 is what Honda recommends and that is what you should use conventional or synthetic.
If you can afford it, full synthetic. I use valvoline synpower, but any full synthetic would be good like mobil 1 or royal purple, but full synthetic really isn't necessary. especially for a daily driver. synthetic blends are the best of both worlds because they are cost effective, but better than conventional.
Use the exact weight that is listed on the oil fill cap which is more than likely SAE 5w20. You can use conventional or synthetic, which is your choice. Also use a quality oil filter such as Purolator, Bosch, Wix, or Honda filter.
No. It should say the grade in the Manuel (5w20 most likely) or on the oil cap. Synthetic is not mandatory in any engine.
No, absolutely not, that is the wrong weight oil for your Civic. Use 5w30 weight oil. You can use a full synthetic but use the correct weight if you want this engine to last.
The recommended oil change for a 2002 Honda Civic is every 5,000 miles. If synthetic oil is used oil can be changed every 10,000 miles.
Most firing orders of conventional four sylinders is: 1-3-4-2
depends on climate, But I run 0W-30 synthetic all year round no problems.
The benefits you can only get by voting/your civic duty