How Stoic is Malcolm Reynolds?

Very, by my reckoning.

First some introductions, for the uninitiated, Malcom Reynolds is the fictional captain of a freighter named Serenity and her crew in the series television series Firefly and movie Serenity.

He is driven by his sense of virtue and an intense desire to call things by their right name.  He may not respect an occupation, but he can respect the person who does it.  He is largely unperturbed by the things that go on around him.  He is aware and responsive to the impact of his action on humanity.  Yes, he is a thief, but he will risk his life, livelihood, and reputation to restore stolen medication to a town that needs it.  His idea of the good life is flying under the radar of the authority which could take his life, love, and ship, but he regularly puts it at risk to save the life of a crew member or to speak truth to the power of the central government.

Operative: Are you willing to die for your beliefs?
 Capt. Malcolm Reynolds: I am...
[they draw. Mal fires first, and the Operative is forced to take cover]
 Capt. Malcolm Reynolds: 'Course, that ain't exactly plan A.

Over the course of the series we see the sense of virtue manifest in Malcolm as compared to and contrast against the received morality of the Christian Shepherd Book.  Perhaps my favorite of their interactions arises late in the saga,

Shepherd Book: I killed the ship that killed us. Not very Christian.
 Capt. Malcolm Reynolds: You did what was right.
 Shepherd Book: Coming from you that means - almost nothing. [grin]

Malcom, at other times, seems rudderless.  Strike that, he claims to be rudderless.

Capt. Malcolm Reynolds: I got no answers for you, Inara. I got no rudder. Wind blows northerly, I go north. That's who I am. Now, maybe that ain't a man to lead, but they have to follow. So you wanna tear me down... do it inside your own mind. I'm not trying to tear you down. But you fog things up. You always have. You spin me about. I wish like hell you was elsewhere.
Inara Serra: I was.

I would say he has a rudder, what he lacks is a destination.  Two very different things.

So call him an accidental stoic.  At least, I think he is one.  One that arrives at his philosophy of life through the things he has lost more than deep study.

If you have not watched the series, I highly recommend it.  It is available for streaming on Netflix.