This document can fulfill your requirement partially.
Your first requirement is well discussed in this wiki content. Check the wiki again and compare your settings again. I have tested it many times before and it is working perfectly fine as per this wiki.
You second requirement is not a business process. Freight charges should goes to vendor account.
MIRO is used only to post invoice to vendor. if you do not want to post invoice, then why you are using the as freight charges.