Hello, french cousin! ^^ I'd answer you in French but since this is an English forum... well, you see.
- Runeword Burn : I play melee that's why I don't have any fragment's but the burn still applied to Runeword Explode or only to the
Unfortunately, Runeword : Burn is a Projectile Modifier. It can't affect your melee attacks.
- Sacred Rage + Fire Ring : I have a bug and some difficulties to see if it's only visual or not. When Sacred Rage proc the visual effect of Fire Ring but Icon of the buff don't. And I don't know if I had to recast it or not... And where I can report this bug...
I just tested it. When Sacred Rage activated, the visual effect of the Flame Ring vanished, but its icon was still visible, and it was still damaging nearby ennemies.
I hope this answers your questions. ^^
PS: I think you have to post a certain number of posts to choose your avatar (10 or so.)