Request for rules clarifications

[Heebs13]

Hey guys, I'm new to red but I have a couple rules questions I'm curious about. They will probably never come up for me because I'm pretty casual but I just want to know.

#1

Let's say I'm a Paladin and I want to PK a bard. Now, I'd be insane to NOT try to root him if I want to successfully kill him, right? Now let's say he's in the middle of a swarm. Is rooting him considered intentionally causing xp loss? Do I have to sit and wait for him to finish his swarm before I'm allowed to attack him?

#2

I'm pretty sure I know the answer to this one, but the rules say you can't interfere with a raid target unless you have at least 12 people or more, then gives an example of training the raid. Does interfering with the raid target include any and all pvp action, such as a few players attacking the raid's clerics, or is it specifically doing things like training, dispelling slow from the boss, etc? Are you essentially barred from taking any pvp action against a raid while they're in the process of pulling / engaging a raid mob?

Thanks in advance.