Full Migration 2008R2 -> 2016
f I understand what I've read so far I can detach the databases from 2008R2, copy the files to the new 2016 environment and attach to them... enable query store and up the comparability.


No. Dont do detach/attach. Instead use backup/restore.

If you have a very tight migration window, setup logshipping or Mirroring and just do a cutover to new instance.

I have detailed about pre and post steps for migration.


  How to migrate the user records with their passwords


Use dbatools to help you out in migration. For logins, just use Copy-DbaLogin.


  How to migrate the Linked Servers with their passwords


use Copy-DbaLinkedServer