move dummys is less combat bug I think..

[Firstaidkit]

As a Shadow Priest I get lots of combat bug

Periodic Damage, that's the reason why all Shadow Priest's get lots of combat bug.
Even if you use the "out of combat" NPC, that Periodic Damage will put you in combat again.

Yes, I know but also

because of Vampire Touch and Vampire Embrace healing all my party members and give them mana back. And if one of my party members is combat stuck I get it too.

This is why Shadow Priest is the class that gets most combat stuck :'(.

[Peekaboo]

Block people from joining a BG when in combat, GG.

Even if the ooc NPC doesn't work, you still can use the portal to the other Mall to get ooc, and join afterwards.