The other day I found out that it's impossible to use yum on a Red Hat machine with an expired RHN subscription. It proved quite unpleasant to work my way around it, as wget was not installed.
Of course you should have a valid subscription, otherwise you won't get security updates. It happens every now and then that I run into people that run five year old RHEL installations which they have never updated because they either are too cheap to pay for it or have never heard about CentOS.
Pretty soon we'll need a valid subscription to start daemons, something made possible by "improvements" like systemd.
It don't understand how you made that conclusion.
This subscription model is becoming quite the rage (Microsoft, Adobe, Red Hat, etc) and this is leading real fast to absurd situations like in the novel from Philip K. Dick (Ubik) where the guy has to pay a few dimes each time he wants to use the door of his apartment.
You have to pay if you want to continue to get binary software from Red Hat, you can always get it in source form even if you're not under a subscription.