extended roles manager plugin idea

hello,

i am using the roles manager plugin on my site. i find however that it lacks in one way. it doesn’t let you chose which role is allowed to edit or publish posts in certain categories.
i know that there is a limit-categories plugin (also by owen winkler), but i tried getting it to work with wp 2.0.5, and even with all other plugins deactivated i would just get a white screen when i wanted to got to manage->categories.
so how easy would it be to kind of integrate those two plugins into one? instead of the ‘edit posts’, ‘edit published posts’, ‘publish posts’ and ‘edit others posts’-buttons you would have a table where you could set each of those capabilities individually for each category and each role.
i’m not sure how useful this would be to other people, though.
i’m setting up a travelblog. i am the only one to be able to post to categories ‘travelogues’ and ‘photoblog’. then there is a category ‘travel stories’, where users can post their travel experiences, but are only allowed to edit their own posts. the last category is called ‘travel guides’. here every user can write guide-book-style posts, but i need everybody to be able to edit these posts, as i want them to be kept updated. i just don’t know how i could manage to do all this.
bo