Board Thread:Manga/@comment-24930713-20151109044731/@comment-5774380-20151111220310

If Levi becomes a Titan he would very likely retain his abilities, even in his mindless phase. Just remember Eren after his first [seen] transformation during the Battle of Trost, when he was randomly killing Titans around. Mikasa noted that that "Rogue Titan" somehow was using fighting techniques, the same that Eren learned during his military training, even when at that point he was acting by pure instinct; so it's very possible that the same would happen to Levi.

That "electric arcing" is anime exclusive, I haven't seen any similar in the manga. Mikasa and Kenny also possess the awakened power and none of them has shown something like that either. As far as we know, the awakened power is not something that they turn on and off at will, is just how they are now.

About Ymir, I don't think she has been eaten. My guessing is still the same than always: she is alive, but probably being tortured, in the Homeland.