No better or worse than any other major brand oil. Honda does not refine oil, they buy it from a major oil company that puts their name on the can.
With mass modification. Probably not worth it. Answer: No they will not fit. The shape of the bumper cover is different, will not mate up with the different fenders, and will not fit on the different...
probably not, the accord layout changed quite a bit from 1987 to 1993
the car with an H in the middle of the hood and/or trunk and says accord above the rear bumper
no because an accord headlight is much more longer than a civic headlight