Of course, in more testing, I found that RemovalTool still occasionally failed to remove the folder. I found that the folder removal was being blocked by a hidden .DS_Store file in the folder. I have no idea how that file was getting there (something about my Casper-based installation packages, no doubt), but it's something else to check for when preparing your removal scripts.
Haven't double-checked the Acrobat Pro XI RemovalTool's behavior yet.