Sorry - it probably came off sounding a bit more severe than I meant it to be. However, Apple removed the permissions repair function/ability to mess with permissions for security reasons according to what I've read, and very, very few people actually need to get that capability back. That needs to be made clear - otherwise people may mess with something that could get them into trouble in the wrong-headed belief that they've somehow been deprived of a needed function with El Capitan. I have no intention of disabling SIP on my own system - I'm not a developer and as far as I can tell, it's not something I need to do in order to have a functioning system. There may be a few applications out there that have difficulties because of this - SuperDuper was one of them, although they seem to have solved that problem as there is now an El Capitan capable update available for download.
As for the secure trash delete - that seems to be related to flash storage and the different way file deletion works on flash storage. I doubt that "secure delete" is coming back either, given the general move to flash storage.
Info about that whole issue:
http://apple.stackexchange.com/questions/1...essary-for-ssdshttp://lifehacker.com/how-to-securely-eras...os-x-1580603733However, there are workarounds using the Terminal, if you really feel you must:
http://www.macissues.com/2015/10/03/how-to...-11-el-capitan/