For searching YouTube EDU Content using API V3

For searching YouTube EDU Content using API V3

I am under implementing the application for searching YouTube EDU content
using YouTube Data API V3. I used below API for searching YouTube
Contents, but I faced two problems.
https://www.googleapis.com/youtube/v3/search?part=snippet&channelId={CHANNEL_ID}&maxResults=10&order=rating&q=keyword
The first, I want to display not only title but also author, view count
and total playing time. When I use the 'part=snippet', these information
is no exist in the result metadata. So, I try to user other things that
allowed at the 'part' and I get the below result.
snippet : Well done, but author, view count and total time are not included.
contentDetails : 400 Bad Request
player : 400 Bad Request
statistics : 400 Bad Request
status : 400 Bad Request
The second, I want to search the contents within specific YouTube EDU
category. but, I can't find the proper channel_ID corresponding to YouTude
EDU category data in the API V3
https://developers.google.com/youtube/2.0/developers_guide_protocol_education#Categories
Please, help me how to resolve these problems.