I would think PVs are ok, because if they're only shown on Japanese TV, there's no other way to get to see them, right? So it's not like it's taking money away from the artist or anything...
Also IMO live appearences would be ok, too; after all, if there's a programme on TV, you could videotape it and that wouldn't be illegal, would it? Except for cases where a live show or part of one has been released as part of an official DVD that is for sale... but as was pointed out, that's often not the case.
Concert clips recorded by fans would be ok because they're not copyright to anyone. Although if the band has said they don't want people recording in their concert and people go ahead and do it anyway, that's really disrespectful and I can only say don't encourage it.

(I might be persuaded to look more kindly on people who do that just for their own personal memento, but for those who post links in public, I'll bite my thumb at them...

)
Actually, PK, your point about the pictures had occurred to me, but there's nothing anyone can do about that in fact. I suppose technically speaking people ought to post the link to the site where they got the picture -- but anyway, most sites watermark their pictures so you can see where it's from. I mean c'mon, there's got to be some "freedom of information"!
If anyone was to get mad about the "artistic" use of band photos I would have thought it would be the photographer who took the pictures, rather than the band themselves! Unless the pics were being used to use the band to promote a product or something... but otherwise, they are just for a decoration, yes?
And of course if a band has given permission for their songs to be put up for sample, that's fine.
Phew! ☝ I'm not knowledgeable about this... most of the time I'm just guessing...

and after all I'm as selfish as the next person and just want "more music! more pics! more videos!"... although of course I want and try to support the artists where possible, it isn't always possible and yet I still want... so I try and put that to one side and make an objective thought about what would/wouldn't be allowed on J-ref.
