Give some idea about WCNA

1. The official study guide book covers the content of the exam fairly well: http://www.wiresharkbook.com/studyguide.html
2. I suggest reading through the info package materials here: http://wiresharktraining.com/certification.html
3. The curriculum is useful/important knowledge for sure. In my opinion the certification itself isn't well-known enough in the industry to be of much value right now professionally, though. Get it if you have all your Cisco certs and have time to kill, but definitely don't prioritize it over CCxx if you're in network administration and this is to add to your professional worth in the industry.
4. I don't believe so, no.
5. By validates, you mean considers when hiring? Not many, at least in the sense that I've never seen it referenced in job ads.

The WCNA kind of breaks my heart to be honest. The content speaks to exactly the kind of network analysis skills that are lacking in the industry, but it's been executed on such a small scale and in many ways poorly in my opinion. If it was done hands-on like the Redhat exams, through a resident/credible vendor like CompTIA or even Cisco, it could be something much greater than what it is.