No, the plugin doesn’t have such feature. But, there are many free plugins available that can resize images on upload to specified maximum size and JPEG compression. One of the plugins that can do that is Resize Image After Upload.
Yes, since GD bbPress Toolbox 1.4. But, when updating, you must recheck all plugin settings depending on roles, and select roles you want and save. When dynamic roles are used, normal WP roles are suspended.
Yes. If any of these plugins (GD bbPress Attachments, GD bbPress Tools, and GD bbPress Widgets) is active, GD bbPress Toolbox will attempt to disable them on activation. If that doesn’t happen, disable them before activating GD bbPress Toolbox Pro.