He does see Luccio do it in Dead Beat and internal monologues about how there's a big difference between him and her. He does get closer to that level of precision with his blasting rod, where she didn't appear to use a focus, but Harry was already getting more focus and control of his fuego spell. I wouldn't say he learned it from Luccio. I'd just say Luccio is a bench mark for what a wizard can accomplish after a lifetime as a combat specialist.
Ok, so maybe he is inspired by her. He gets the idea that a waterjet can cut better than a fire hose. Though I would not rule out her giving him a tip or two, like a coach giving a pitcher a tip on his grip for a split finger fastball. Still requires work on his side.
I don't think escalation of power is necessarily inevitable in serial fiction broadly or even serial fantasy fiction specifically. I do think it's almost necessarily inherent in the framing of the idea of the Dresden Files as Jim has talked about how he broadly conceived the idea. He's said things like it's about the young hot heads who haven't earned respect yet, he wanted a wizard who threw fireballs (I'm assuming that's a direct DnD reference), etc.
Yes, Jim is obviously a gamer. two parts stand out - where gaming with the Alphas, Harry says they stand at a certain distance, and the fireball died out right in front of them, and Harry disapproved of the exactness. In early AD&D, a fireball was a 20' radius sphere - launched carelessly into a small room with heavy stone walls, the blast could be funneled out right over the casters. I think Harry would prefer having to make sure the group ensure they were not hoist by their own petard. Jim likes fire having to follow physical laws, he spoke to Murphy about the neat hole the Hellfire burned, saying the control might be more difficult than evoking the fire.
the second is where Harry tells Susan in the Erlking's lair they are facing goblins, and she says "Shouldn't you be able to take about a million of them?' or something to that effect. In early AD&D, at least, when fighting very weak foes (less than 1 HD) a fighter got as many attacks as he had levels. So for something like a goblin, a good fighter will be chopping them down like wheat. Harry replies they are tougher than their reputation. In AD&D orcs beat goblins, and hobgoblins beat orcs. Butcher's goblins are tougher than Gygax's.
One thing I like about how Jim handles power escalation, is that Harry, who was always way more powerful than "tiny fairies," to quote Bob, is still vulnerable to them after getting so much more powerful. And it's really enjoyable because it's not like Jim is just nerfing Harry to make them still a threat. Tiny fairies killed Aurora in book 4. Harry wouldn't have to worry much about a pixie, but a swarm is another matter entirely.
The old "Pack of wolves beats a grizzly".