You don't need any of that. This is all you need:

  # Generate key
  $ gpg2 --card-edit
  > admin
  > passwd
  change both user and admin PIN to a secure password (can be the same, it's called PIN but you can just use a regular alphanumeric password)
  > key-attr
  choose RSA, 4096 (or whatever you consider sufficient)
  > generate

  # Add this to your .bash_profile (use GPG agent instead of SSH)
  export SSH_AUTH_SOCK=$(gpgconf --list-dirs agent-ssh-socket)

  # Export your SSH public key
  $ ssh-add -L