Wormtail didn't kill himself - the hand Voldemort put on him killed him - thus, as I see it, Voldemort killed him. Probably some kind of spell on the silver hand.

Dumbledore really did kill himslef, by putting on the ring, but that was an accident, not suicide. As for having Snape finish him off, that is definitely for the greater good - it protected Snape & yes, even nasty Malfoy, from Voldemor, and Dumbledore was on the verge of death anyway.

No evidence that she is glorifying suicide.