That seat angle! No wonder the previous owner got rid of it, I would be lucky to pedal 100 yards with the current setup. Lots of used bikes have funky setups that go a long ways toward explaining why the person decided to get rid of it.

If you get tired of the paint job, but want to preserve and protect the original, I would consider some spray-on Plastidip. It comes in an infinite number of colors (even glow in the dak and "chameleon") and will actually protect your paint underneath. I have done it on a couple of bikes, cost is maybe $15 for 2 cans, and the stuff comes right off using Goo Gone, it peels right off.

Parts-wise, go ahead and upgrade anything that you don't like, just be sure to keep the original part on hand. I don't see any downside to upgrading a few things, other than the cost of bicycle parts, which like buying custom car parts, really adds up. I would venture to guess that even though I have close to 10 bikes, I've spent more on parts for them than on the bikes themselves originally.