If your blog posts are similar to this post, you’ll probably be fine. In this post, you seemed transparent about your thoughts and didn’t seem arrogant. Although, I do agree that something like a blog title could be taken out of context. Maybe you should share the title you’re considering in your post or with friends so people can provide feedback?
Similarly, I’d guess that if you explain your reasoning and confidence in your claims, you’ll be more willing to update them after publishing. Then I’d guess you’d be less likely to feel like you’ve staked your reputation on a statement.
And if nobody reads it, so what? That would be the same outcome as not publishing anyway.
I don’t know enough about how your posts would affect your career. But unless your audience is huge, I’d presume you could delete your posts before you apply to jobs.
How irrational was it to be concerned about long covid pre-vaccination? That was my mistake. I presume I should’ve done something differently. But I don’t have much medical knowledge or a strong intuition for how to analyze a study.