I don't like K&N filters, every motorcycle that I've owned that had one had tons of dirt in the carb, the paper and foam filters do a much better job of keeping dirt out, I personally like foam the best, the let air flow like a K&N but filter better then any other filter I've ever used, they are hard tho to find for most cars, you might check in to what the dealership charges for the filter, not sure if there is anything special about it for the insight but it might be worth spending the extra, if you look online at places like
Majestic Honda - The Internet's #1 Honda Automotive Parts Store then it's only $15 for the factory air filter, also the insight has a timing chain, not a timing belt like the civic's do, so you are safe there as long as the tensioner has not wore out, but Honda has been putting timing chains on motorcycles for over 50 years so I think they figured out how to do it right as the timing chain tensioner looks almost exactly like one from a Honda motorcycle.
As far as the gear oil goes, Honda does sell a MTF that is supposed to be what was in it from the factory,
http://www.honda-tech.com/attachment...1&d=1255110463
Otherwise I read on
Insight Central: Honda Insight Forum that Amsoil MTF works really well, it is a bit thiner then motor oil and is supposed to work in trannys that call for motor oil as the gear oil and for older Honda's that is what is called for, Motor oil, 10W 30 seems way to think tho, the same 0W20 as the engine calls for seems closer, but a synthetic MTF will be even better.
As for 0W20 motor oil for the engine, can you get Amsoil? I think they sell that weight of oil, otherwise Royal Purple has a 0W20 and I had good luck with both of those brands, pretty much any 0W20 oil is going to have to meet current SAE standards and I think that weight is pretty much only sold as a synthetic.