i agree with these
Posts Count & Join Date Under Username – just post count and join date on profile.
“Report” Option – It would be good for moderation.
Attachments – but just using the Add Media button , ive been messing with this lately.
Things that should be a plugin
Private Responses – kind of a toss up , its not hard to create though. or are you talking about Private messages??
“Like” button – bbPress has a favorites option , like buttons per reply should just be a plugin, there are nice options for plugins though.
dictate if there are “new” or “unread” posts – there is a lot of options in plugins for this and they are quite different too, it really depends if its good for users to have an option on what they want or what.
Ability to “Quote” users – we have threaded replies as an alternative. it could be a feature in the future , but i think it should stay in plugin territory for now.
things that are easily possible to create in my opinion
Icons for Subcategories that help to differentiate between subcategories – simple css
“New” icons for new posts – show icon from date of creation.
“Sticky” icons for stickied posts – simple css
“Hot” icons for posts that are popular -show the label when a reply level hits
Ability to Rename bbpress specific vernacular (IE “Last Post” in place of “Freshness”) – put the templates in your child theme / create a custom language file for your site/ custom function.
Format Categories vs SubCategories in Traditional Forum Style – there is three ways you can have this functionality.
Signatures – you can create a custom text description box in your profile and then just show it after your reply content with a function.
things that are already in bbPress
Sort Forum by Recently Updated, Most Replies, Most Viewed, Etc. – bbPress views does this.
Basic editor for responses including format help – the default quicktags seem basic