^ I'm glad you have an open mind about this stuff!

Cables: inspect the end where the cable itself (not the housing) attaches to the brake lever. That's the only place I've ever seen a cable fail. If there are signs of wear there, replace it. Otherwise, it's as you said.

Brake pads: they're not really rubber, but some synthetic stuff that doesn't age very much. Still, if new pads are even a little bit grippier than old ones, what the heck, right?

Repacking a freewheel is pretty much impossible for anyone short of an expert, and not worth the effort for anyone. Drip some oil in there; maybe squeeze some grease in from the back, and be done with it.

Chain -- clean thoroughly and lube; that's all you have to do.

Tires -- If you see safety issues, of course you should replace them. But cracks in the sidewall don't mean anything. What you want to look out for is tears in the casing. You can get a tear in the casing of a tire you installed yesterday; if so, replace it. If your 40 year old tires are in perfect condition, even with cracks in the sidewall, leave them. They will wear out soon enough, and you can replace them then.

Tubes-- no, you're all wrong on this one, sorry! The tube has one job: to hold air in. As long as it's doing that, leave it alone. Age is not a factor. You can get a puncture in any tube regardless of its age. When that happens --whether ten days from now, or ten years from now-- that's the time to replace it. Actually, I patch tubes five or ten times before replacing them. I have 40+ year old tubes in some of my bikes, and not for sentimental reasons; as long as they're good, they're good.