Maybe I'm missing something....weren't most of these recommendations part of Pres. Obama's charge to gov't agencies back in 2010 when he instituted hiring reform and the implementation of Pathways for students and recent grads? The IC is always an exception in terms of time to hire, but my friends in non-IC agencies have said that they have seen dramatic decreases in onboarding time over the past two years (recent shutdown notwithstanding).
Agree that social media usage is a must. The State Department does a fantastic job with social media (they're all over Facebook). They even host chat boards for potential hires on careers.state.gov. The CIA recently redid its website to be much more applicant friendly - including a "fit" quiz.
But just a few days ago I visited both IRS.gov and NIH.gov with students, and both sites still reference the long defunct SCEP and STEP programs. And while I know that they are not likely to hire in the near future because of budget cuts, the FBI's hiring information on their current website is a mess. That is the kind of stuff that turns off interested Millennials. They'll deal with the rest of it, but the information must be accurate and up to date.