1. Oil, leave it
2. nuts/bolts etc really to cover with WD-40, or ACF50 is even better for that. Don't do your discs though. Techincally anything metal will prefer it on there rather than exposed
3. Sure, remove the batter, keep indoors, good plan.

It could be argued to use a fuel stabiliser, but I've never done so.
It could be argued to block the exhausts with a rag to stop any spiders/rats etc
It could be argued to have the wheels off the floor on paddock stands

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