DK is great, either way, but the lame leg does add to the character at this point. It is a visible connection with his painful past. Perhaps the leg will heal when his heart does. Just consider he has one foot in the past, and one in the future. Disha is forcing him to consider the present.
At some point, it would be appropriate to have the injury heal, and DK walk tall and proud, for all the right reasons....
As for line deliverence- well, as I'm stuck reading subtitles, I just wouldn't know!! But I have seen an off moment here and there. It is to be expected- he'll continue to get better with age, as long as he gets decent roles of many different types.
-DKaddict