There are definitely links between the ring and the element, but as ever in Tolkien, they are subtly and poetically drawn. So both Boro and Mithalwen are right to my mind - there is the poetic and inspirational interpretation of 'fire' as courage and morale-boosting, and also the real physical element of fire.
The poetic may include Gandalf's ability to inspire and to lead, but also the spiritual element within the world he lived in. I don't think it's any mistake that he held the ring of Fire and that he was the only character we know of who went right back to Eru (we think) and was sent back whole again; was the fire within the Secret Fire?
The physical can be seen by anyone in his ability to make fireworks of course!
The choice is up to the reader. I'm having both
The next interesting question is as Mithalwen says, whether or not the Ring accentuated latent powers or created them within him? And following on from that, was the Ring created with some kind of foresight of his arrival in Middle-earth? What did Celebrimbor and Cirdan know about?