How many of you check the water level in your battery. There is no such thing as a maintenance-free battery, and yes you can add distilled water to them. They had to put the acid and water into them to begin with. They access plugs are usually under the strip of writing.
The reason you need to...
I have separate rims for snows and summer tires, both with TPMS, Never have had to reprogram the senders, after a couple of miles they lock right in. Love it as I can do my seasonal tire change myself.
Was transferred from Pearl Harbor to Ballston Spa New York in December of 80. Drove a 1980 Subaru wagon, 4 speed manual, 4 wheel drive from San Francisco with two children under 2. It was fun.
I not sure about the engine oil flush, you change it every 6000 miles, why do you need to flush it? The power steering flush I can see doing. Fuel injector I am doubtful on unless you either 1) use cheap fuel (as they have additives specifically to clean the injectors and 2) the car is not...
The hydrogen and oxygen gases produced by the battery are not sources of ignition. They are fuel. Sources of ignition would be flames, sparks, etc. If there are not any sources then the gases are not a problem