Yes that interpretation is correct.

Re. Message body. To avoid having the process of open message, read message, open next message, etc, for example when you have several dozen combat result emails:
- on the inbox screen have an "open all" button
- this displays the first unread message (subject line AND entire text of the message) then scrolling down the page you have some border/divider or something, then the second unread message, etc, up to a total number of messages equalling however many there are, or whatever limit is imposed by memory, programming, good sense or whatever.

I'd be quite happy if this feature was an option in the settings that is switched off by default, because it may make the inbox too complex for some.

Cheers