I'm the opposite to @Jeremy in this respect. Having come from phpBB where this information was always shown, I've got the join date, post count, likes received, trophy points and some custom fields (PlayStation, XBox and Steam usernames) showing.
It's a personal choice and something you should decide what is right for your community.
On the forum list? I've never went through the trouble. I'm not sure it's worth the effort to hide low activity.
I do hide the message count but show likes received. Quality over quantity. I've always felt showing post counts put to much emphasis on who talks more. Lots of people talk but all they do is blow hot air around.
You can have a member with a 100 posts and only 10 of them are useful posts or a member with 10 posts but 8 of them are useful. I'd rather show the member 80% useful post has more likes than the guy with 10%.