First of all, it sounds good, and looks OK to me.
So, that slightly more arched and supinated position that I take it you're calling "suboptimal" is reminiscent of a lot of concert guitarists and flamencos I see these days. The straight but slightly cocked wrist you seem to favor, I'd call "old school". Neither are "wrong", to my eye and in my belief, nor would anything in between be wrong, if you wanted to adopt a compromise. Don't take my word for it, though--look around on youtube and see for yourself, or better still, consult a teacher.