1. The din of gerama- reb shlomo zalman has a big arichus why it is not gerama based on the gemara in bava kama that is mechalek between gerama dnizaken and deshabbos demeleches machsheves asruh torah.
2.For shabbos candles most poskim hold you can use electric lights being that the din is just to have light. Mah sh`ein chanukah most poskim assur using electric lights because there is a din in hadlaka