1. There is a Bing Webmastertools [bing.com] smilar to google's. 2. See here [bing.com] the process to disavow. 3. There is no way to add a txt file, so the system is useless. I cannot add thousands of URL's by hand!
About a year ago I think I read somewhere that Bing's algorithm (unlike Google's) never counts a backlink against you, but simply ignores any that are questionable. If this is true, then you shouldn't need to use their tool anyway. On the other hand, my memory could be bad, or what I read is wrong, or things could change in the future. Does anyone have any better information about this?