The reason why we need api command instead of api-get is simple: We need to do HTTP GET, POST, PUT, DELETE requests.
I created api command, with new options --get, --post, --put, --delete, --patch, --file="local path", --data='key1=value1', --header='headercontent' , original --pretty option and server options still work.
For api --get, --post, --put, --delete options, I did some testings using command line tools.
I created a review request draft and used my --get, --post, --put and --delete options, they all worked fine.
I posted several files to the review request draft using --post and --file options and they worked.
I don't think our reviewboard APIs support --patch at this moment so I just left it there in case one day it will be useful.