Lights on Yom Tov & Yom Kippur

Question

1) if you program your electric lighting to go off just before candle lighting on the second day of yom tov can you then turn it on and make a bracha on the lighting? Can you turn on lights on Yom tov if there is a need? 2) With regard to Havdalah on Yom Kippur, how does one light the Ner? Can you light your havdalah candle from a yartzeit candle? If you cant do you skip boreh "m'oreh haAish"? I would appreciate knowing if there is a variation for Sephardim and Ashcenazim. Thank you this site has been very helpful for me.