I'd say all the hosts and admins should care of is when they see OBJS message... Other things are most likely temporary problems from the client.
But when you're building a layout and see the message "A new guest is connecting" you should stop and wait till the guy comes online. Actually I always thought that's why there is "A new guest is connecting" message, because when that message shows, the one connecting has just started to download the layout. But I don't know, might be another reason.
Anyway the shortened messages are easy to understand if you think just put some basic logic on it.
Also... To show all the info LFS needs shortened messages, because they have to fit in the chat, don't you think? The best way to report an error is to think of shortened code of the message and have these codes recorded somewhere, or else you would have to spam the chat with too much unnecessary messages, IMO.
So I'm -1 errors to be fully reported in the chat. And about their meaning.... I don't really think it's necessary to have them all explained. Maybe just the ones, that hosts need to know about, and can prevent (so the admins that care about their servers can manage them even better).