I do agree that these two types of sin are different.
I'm not sure how much more there is to say about that, so ... I think we are doing good.
At least in understanding each other.
In a way, I have thought if it (and I will be clear this is my own mind thinking, not Orthodox teaching, though for all I know, the Church MAY agree ... or may not or may not have a position) ....
But my way of thinking is something like there are sins of what we DO and sins of what we ARE.
Keeping in mind, please, that I have a broader definition of sin (hamartia) ... not ONLY "transgressing the law" but also including all of "missing the mark". And since the "mark" we aim for is no less than being like Christ Himself, we will ALWAYS fall short of that goal, in ways large or small.
Even if we act as Christ would have done in a particular situation, we may not do so with exactly His motives. Or even if we do so with His motives, some stray thought may also influence our attitude the tiniest bit.
Now that thought, if it is only a temptation, is not, strictly speaking, a "sin" as in something that needs to be confessed before God for forgiveness.
But it STILL shows us that we continue to fall short of Christ, no matter how close we might come, and teaches us that our only proper attitude is one of humility, realizing that no matter how much "good" we might happen to do in this situation or that one (remembering that we do "good" ONLY by the grace of God anyway) - that we still fall short of Christ Himself, and always will.
This is how we can get the understanding in the heart that we have NO righteousness of our own. No matter how close, to the glory of God, we might come, it is only by His power and it is STILL not the righteousness of Christ, which you are right, in this life, we do not expect to achieve. We expect to struggle with temptations and shortcomings all of our lives, until at last we find ourselves in the Presence of God at the end of this earthly life.
So we will never be righteous in ourselves.
Sidetracked a bit there, sorry, but I hope that made sense.

Oh, and the rest IS Orthodox theology - I'm just not sure about the part where I said I look at sins of how we are, and what we do.
Your alcoholic's drinking while he is still an alcoholic might be considered how he IS, since he can't yet overcome the flesh and not drink (I'm guessing here, since I've never been in that position and have no experience) ... just as I would also say there are things about us that make us fall short of Christ all our lives, and that is who we ARE, not sins we choose to commit.
But they can still grieve someone who wants to be as Christlike as possible. Though on the other hand, remember pages back, I said that we can't go getting all surprised that we are not perfectly sinless, because that would be pride, as though we could be.