1. Quote? Do you mean this:
"This ship... is it his weakness? It should not exist, yet it cruises the darkness between the stars. He tore it from the mass shadows of Malachor, along with his fleet... that is a measure of his power."
That implies nothing of the sort. He simply says it should not exist but does due to Nihilus lifting it from the surface of Malachor.
And sure we can assume that, but it has no basis backing it up, and the Ravager was the only ship Nihilus was ever on, so I seriously doubt that.
2. There was a flow of power he drew from the Ravager, I checked, but no mention of his fleet.
Defenceless or not, he still one-shot millions across the entire globe with a thought. It's one of the best feats ever, even if you attempt to lowball it. And yes, it's confirmed Nihilus can ravage worlds just by thinking:
Amazingly dark and devastating powers are the purview of some of the greatest Sith Lords of the Knights of the Old Republic era. They devastate and consume entire worlds with a thought... Average beings stand no chance of stopping these ultra-powerful monsters of the dark side.
-Power Beyond Belief: Using Ultra-Powerful Sith Lords in Saga Edition
As for Telos, he may simply have been too far away to do anything.