When using the rules tag, is it necessary to tag pp staff, judges, infernals, etc for a ruling? Or is this more like the old forums, where the topic gets locked when a correct answer is given, or an infernal makes a ruling?
I mean… pp staff is monitoring the rules tag, right?
Im newer to this forum type, so would also like to know this. 
I’ve frequently tagged Infernals for Warmachine rules questions. It’s their job, so as long as it’s relevant (and presumably, as long as multiple people don’t tag in the same thread for the same question), it should be okay.
Generally, rules threads are locked once the correct answer is given and/or once a staff member has provided a ruling. They’re not instantly locked, but generally it’s pretty obvious when the question has been correctly answered. Locking didn’t always happen early on, but staff has been more consistent with locking things for the past few months.
It varies. Generally you don’t need to tag the Infernals for rules questions as they do check in on the rules tag fairly regularly, but Bulldog (elswickchuck) has stated a few times that they don’t mind being tagged on rules questions.
The Devs do check in on the forums but they don’t tend to comment as frequently as they are pretty busy. Rules questions are usually answered by an Infernal so I would refrain from tagging devs with rules questions since the Infernals have the ability to get in touch with the team if needed.
Quoting Chuck from a different thread today:
So, there you go. 
If it is tagged as Rules, we see it. We don’t need to be tagged. But like Chuck has said, he’s amenable to it.
Since you specifically said this about Chuck, are we to interpret this so that you are less amenable to it? Just to be clear so that we don’t bother you unnecessarily.
Unless specifically trying to speak to or get a response from someone I lean towards not tagging staff or Infernals for general questions. Adding the appropriate tags allows for easier reference and multiple staff to see it.