My opinion on oil has changed a lot. Since this is your first and (honestly) you're unlikely to use it enough that you'll need to get it serviced every year or two, no oil. If you were a prolific enough writer that you could afford to have it serviced on a yearly or so basis on your writing alone, then oil would probably be worthwhile. Display piece? No oil. Twenty pages a day? Watch the mechanisms on the inside and apply oil with a straight pin, once, for metal that rubs metal. Seriously. That little. Do Not oil the segment or linkages or carriage rails under any circumstances.

I read the 1955 army Royal service manual, which said to dunk the whole machine in gasoline for ten minutes, let it drain, then dunk it oil for ten minutes and let it drain. These machines were in constant use and the army has a tendency to keep machines in use well past their prime. However, yours is not one of those machines.

I forgot your other questions, so future edit: