Does this doctrine entail that all of our actions, even good ones, deserve punishment?
I’m not sure I have an official modern answer to this question. C67 doesn’t say.
I’m going to give you a personal answer, which probably doesn’t reflect a mainline consensus.
In a sense it’s a hypothetical question, because it is in effect, “if it weren’t for God’s grace, would all acts deserve punishment.” But I don’t know how to answer that, because you’re asking for me to apply a standard that differs from God’s actual standard.
What complicates it is that I think the love of God affects the nature of our acts. Without God’s grace, acts might comply with the 10 commandments, but I think in the end they would turn out to be toxic goodness. That kind of goodness does deserve condemnation.
So I don’t think I can answer a question about acts ignoring whether they are done in Christ or not.
So you don’t think I’m using a trick to avoid your question: I do disagree with traditional Reformed theology’s claim that no one is righteous. In fact the Bible calls lots of people righteous. Check a concordance. There are two exceptions. One is a prophet who is particularly upset about the current state of Israel, and is using hyperbole. The other is Paul, who quotes that statement in a context this is hypothetical. That is, he’s saying that if we tried to separate righteousness from God’s grace we’d all be unrighteous. Yup. Righteousness is only within faith.
The reason the Bible can call people righteous is that Scripture doesn’t use righteous to indicate some kind of moral perfection that would stand independent of God’s grace. Rather, someone is righteous when they do (imperfectly) what God tells them to, within the context of faith.
Traditional Reformed writers give the impression that there is in principle a righteousness independent of God’s grace; we just can’t reach it because of original sin. Hence the claim that Adam and Eve were righteous before the Fall, since before the Fall they could reach it. But I think it’s a mistake to say that such righteousness exists. I think any attempt at righteousness independent of God’s grace would result in something toxic.
Indeed I don't think God intended us to operate independent of him, and thus that this dependence upon his grace is how we were designed to work. That's good, because of course I don't think Adam and Eve historically existed, nor that there was an actual historical event corresponding to the Fall. Rather, we evolved as creatures that learn by trial and error, thus pretty much guaranteeing that we would make mistakes, some of which would be moral errors.