[Gothmog]

I'm sorry if I follow the off-topic question here but I hope you forgive me.

I was under the impresion that he was only supposed to influence the inhabitants of Middle-earth through words of council...

That's my impression too. I'd have to look it up, but isn't that the Istari's task in ME? They weren't supposed to go straight to Sauron and fight him til the death of either him or the wizards. The Valar didn't want to interfere with the dealings of men too much. The men had turned they're backs at Valar and they were on their own. But still the Powers sent a little help an guidance in the form of Istari.

Speaking of Gandalf and the elven rings: Narya was the Red Ring of Fire and fire was a bit of a speciality of Gandalf. Remember the fireworks? Or when he interrogated Gollum and put fear in him using fire magic. Or challenging Durin's Bane presenting himself as a servant of the secret fire. Maybe Narya enhanced Gandalf's powers, but he didn't use it "actively"?

And a little more on-topic: I doubt any mortal could have controlled the One enough to control the Three. The ring itself would soon take over completely. Not even Gandalf or Galadriel dares touch the ring because they know they might not resist the temptation of power. They could not control it, how could Gollum have?