dnf system-upgrade: puzzled with post upgrade tasks

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I recently upgraded Fedora 22 Workstation to Fedora 23 using the dnf system-upgrade method. The upgrade went fine overall. After, I tried to follow the recommendation on possible post-upgrade tasks but it confuses me.

Running dnf list extras: I can still understand having all sorts of fc22 kernels listed, even though they are installed and configured to be booted by grub. Just a little bit weird.

My question is in regards to dnf autoremove, which returns:

 adobe-source-han-sans-tw-fonts                            noarch                 1.004-2.fc23                    @@commandline                  38 M
 jack-audio-connection-kit-example-clients                 x86_64                 1.9.10-3.fc23                   @@commandline                 574 k
 kernel-debug-devel                                        x86_64                 4.4.5-200.fc22                  @updates                       38 M
 kernel-debug-devel                                        x86_64                 4.4.6-300.fc23                  @@commandline                  38 M
 kernel-devel                                              x86_64                 4.4.6-300.fc23                  @@commandline                  37 M
 libftdi                                                   x86_64                 1.2-5.fc23                      @@commandline                  94 k
 lirc-core                                                 x86_64                 0.9.3a-3.fc23                   @@commandline                 1.0 M
 python-firewall                                           noarch                 0.4.0-2.fc23                    @@commandline                 1.3 M
 python2-dnf-plugin-system-upgrade                         noarch                 0.7.1-1.fc23                    @@commandline                  95 k
 recordmydesktop                                           x86_64                 0.3.8.1-15.fc23                 @@commandline                 128 k

Why is that? Do I really don't need them? Why is kernel-devel.4.4.6-300.fc23 listed? I think, I need this package for my damn VirtualBox, maybe not? Is recordmydesktop wrongly listed? Just mark it as user-installed, or what?

Before, when I ran dnf autoremove for the first time, a few days ago, I declined any transaction because I found it suspicious but even kexec-tools was listed among the to-be-removed packages. How can a stupid end-user like me know what to do?

Thanks for your feedback!

edited: I noticed another weird behavior which could have been triggered by the upgrade process but I decided to ask it as a separate question.