In the first season, it is only possible to make magic wiith magic that is already in Storybrooke that was brought fom ET. It is also understandable that Rumple let his leg like it is, because besides Regina he is the only one remembering (He remembers after Emma say her name to him). So it would be not a good time to heal him at this point even if he has some magic left, he wouldn’t spend it for that. In season two are complete other rules. Magic is there, but he is still not healing it, altough everybody knows him (and not like him) and know that the Dark One wasn’t limb. His attitude is staying Mr. Gold and not Rumpelstiltskin at all (no giggling, funny voices. He is the complete opposite of Rumpels behaviour calm and civilzed) and of course always going and looking like he was Rumpelstiltskin pre the Dark One. The question is why? Are this personal reason (Remind him of his old self, before the power corrupts him, trying to be the better man, don’t want to be the Dark One again and avoid magic that cause him to give in more to his Dark Side, staying like that, that Bae will think magic is taken by his father….) or is the prize of magic in this specific case to high? Also it could be that he doesn’t need the cane, but why the show that he is still lame. (I mean Belle tries hard that he his more honesty. Why to risk a fight for that he is know healthy)
And we are sure that he has the ability to heal. (He healed Baelfire,Dr. Frankenstein, Belle)
Heros don't get their Happy Ending!