@sharonyue to remove the panel you have to edit the template.
I do not know exactly where it is but it should something with topic template.
On the old nodebb.org page there was a text with the latest stable release of NodeBB. I guess its v0.7.3 right now but where can we se it. 0.8.x id pretty much dev right?
I like to run a more stable version of NodeBB on my prod sites BTW v0.7.3 works great!