HRC derestrictor box and loom (presumably you mean part #30490-NKD-840 for the mc21 and the HRC loom)

Will this still run the lights? Not with the HRC loom no.

If it doesn't I have read the thread where it can be hardwired into the stock loom. Yes it can be, no I don't know how, Monkey's works fine

It says it advances the timing, do I need to run high octane fuel? No, but detonation is obviously more likely, check the jetting.

Will it still run the oil pump? Yes, it can.
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