Personally, I prefer at least a summary or cliff-notes version of the blog post in the Lemmy post. That way you can get the gist of it and decide if it's worth the click. That also, at least IMO, makes it seem like more organic engagement on this platform rather than blogspam or simply trying to drive traffic to your blog (not making any accusations, but that is a common thing to see).

Not saying that's a rule or anything, just chiming in with my two cents in a general sense.

I would suggest posting your thesis statement with a link. Maybe like two paragraphs?

If it's your own blog you're free to share it in whatever manner you like. If it's not your own blog you should respect the wishes of the author, meaning ask for permission if you want to copy paste the entire blog. Otherwise, excerpts alongside credits to the author is fine.

Just make a link post in the community. Don’t worry about the length, all that matters is if people like the content. There have been people who posted to /r/rust about starting sales for a book they just published that did really well with votes, so pay isn’t always related.

There’s lots of blog posts in /c/rust and /c/programming. Some of the blog posts in /c/rust can be really long. There was one today about async rust. There are also sometimes free book link posts.

Treating people like you want to be treated can be a decent way to evaluate yourself. Just make sure it’s relevant to the community. If there was a mistake, don’t worry about it, stuff is removed all the time in other communities and subs on other websites, and you didn’t do anything wrong.

I tend to read comments here, and many times skip the linked content if nothing really draws my attention. Skipping a summary is a missed opportunity if you want me (or others like myself) engaging with the content.