This was the question:
Can a person with a free subscription access all the posts of another subscriber?
Of course. The only messages by other members they can't access are PMs sent to people other than our hypothetical freebie. But that's the case for everyone, including subscribing members.
The items in the list you sent are perfectly normal, and haven't ever changed. Freebies can read on ANY board, but they can't post on premium boards. They can't read in batches; they have to read post-by-post. Same for viewing messages by author 50 at a time; again, they have to go one-by-one. They can't use All Posts search. (Or, I assume, Advanced Search.)
But there's nothing in any of that suggesting a freebie can't read all of another member's posts, if he wants to spend the time doing so.