so when Emma becomes adept at magic, will she have the same powers as Regina and Rumple?

Well Rumple and Regina specialize in dark magic and Emma represents the light side of magic. While she while have powers, she probably won't be throwing fireballs at people.

In theory she could become even more powerful but I don't really want that to happen lol. So far she has done mostly just protection or candle-related spells, though haha. So I think she'll maybe be better with self-defense? I do hope she tries other types of magic as well too.