Since the automatic question/answer limitations went into place in 2017,
it has been quite rare for the moderators to issue manual suspensions for low-quality contributions. I haven't double-checked but I think in 2018 I could count them on one hand. Suspensions for rudeness or for misusing multiple accounts are more common, but we don't have too many of those, either.
(And a friendly reminder: if anyone reading this paragraph suddenly wants to discuss any possible past or present suspension of another user by name, please go outside and look for pareidolia in the clouds until the urge passes.)
To answer your main question, we do consider both questions and answers when evaluating the quality of a user's contributions. In a couple of cases this year I have used variations on this SEDE query as a starting point to help decide whether a user's recent posting frequency and quality were actually different from what's typical for the site, or whether I (or another mod, or a flagger) had just happened upon a couple of stinkers written by a user whose contributions are mostly pretty good.
I'm a little reluctant to reveal the existence of that database query, however, because I worry it might leave some readers with the (wrong) impression that the moderation team is looking at some magical number. We're not. The goal of the moderation team is to maintain our high-quality community. Nearly all of that maintenance is done by the community itself, through voting and commenting. Only on rare occasions do we have a user who has missed or ignored these community cues. In those rare cases, the moderation team has a reasoned discussion about whether the best course of action is firmer guidance in comments, or a moderator message, or an invitation for that user to write on other people's websites for a while rather than on our little corner of Stack Exchange.
I know it's frustrating that this guidance is vague, but it really is how we do things. The entire reason for having human moderators is to handle exceptional cases.
Suppose I were to answer your question "what is the limit?" by making up some number: a person whose posting record is $X$ would probably earn a manual suspension.
Then in the future we'll find ourselves dealing with an edge case, some user whose posting record is $X-1$, who believes they are immune to criticism because they haven't crossed some magical threshold.
Public arguments about edge cases ("I've followed all your stupid rules, you can't tell me what to do") are also bad for the community.
What I've written here really is (I hope) a fair summary of how the moderation team has been handling these sorts of decisions, and why we've come to do things that way.