Yes. This is bbPress core feature, but it is filter controlled. Using GD bbPress Toolbox Pro, you can easily enable or disable display of the lead topic: GD bbPress Toolbox Pro -> Settings -> Topics -> Various Settings -> Display Lead Topic.
Yes. Open GD bbPress Toolbox Pro -> Settings -> Replies -> Topic tags in reply form, and Enable this option. Once enabled, only the topic author will be able to see the tags field.
The plugin can add quick statistics overview information to the forum main index page. This contains various information: online users, different counts, and it can contain more things through editing of the template. You can enable or disable this block (or you can select user roles that can see it) by using options in the Settings -> Forums -> Forums statistics overview.