1. Give logged users option to add inline images in their new posts and answers.
2. The posting process should be the following:
(1) the user clicking button
(2) You can do it by to ways:
a) opens file upload form and user give the path to his local file and upload it to somewhere..
b) Opens file upload form and user give the path to his local file and upload it to WP media, and after post it from there. But in this case each user must have only its own media, and can't see other files.
3. All changes should be in child theme, or as a separate plugin, to make Bbpress and WP updatable.