Do you have a Fumoto Quickvalve? My oil pan stripped the first time I changed the oil. I replaced the pan and installed a Quickvalve. I can pull the filter from above and drain the oil without tools. I cannot imagine oil changes being easier.
Replacing the oil pan was a chore, though. The torque specs of aluminum is not much lower than steel, but I have stripped two aluminum bolt holes while trying to be careful. I have not stripped any steel holes.
The oxygen sensors are prone to failure. Everyone says that only the factory sensors work and they are expensive, but you can find them for less than Honda charges.
I do not know that it is common with Civics, particularly HXes, but mine has low compression, and as far as I know, it did when I bought the car at 170,000 miles. That is pretty easy to check.
We always encourage instrumentation, which is more difficult with lean burn, but a $5 bluetooth OBD-II dongle and an old phone, or a cheap pre-paid one, can give you a wealth of information, plus you can read your own CELs. If you want to monitor your fuel economy, you need an MPGuino.
At some point I recommend removing the power steering belt, driving a tank, and then putting it back, so you can see if there is any difference. I removed my power steering and the extra effort when stopped does not bother me. It is supposed to provide a barely-measurable increase to power and fuel economy.
I love the HX wheels, but it would benefit from smooth wheel covers. Other members favor coroplast circles or pizza pans. I think pizza separators look better, but I did not like my attachment method. You could also put fiberglass resin on a cardboard circle.
I screwed a rolled-plastic air dam and grill block onto my front bumper, but I like Metro's air dam for his Miata better. He figured out how to attach it without putting holes in his car.
At what speed do you drive? If lean burn works, you should get better fuel economy at 65 MPH than 55. For some reason, I did not think my lean burn worked, so I drove 55 for a year or two. Then I drove 65 for a tank and had a definite improvement. Talk about regret!
I also saw a big improvement cleaning out my EGR passages, although my long-term data was confusing.
Daox sells shifter knobs with built-in kill switch buttons. He has different versions with more buttons, too.
Welcome and good luck!