I still hold that it's incon here.
Firstly, Absol's specific fear manip having any more affect than, say Genkishi's killing intent goes against the mechanics of dying will flames as a whole. His fear manip isn't going to randomly bypass an entire mechanic where one must accept and be willing to die to bring out their full strength.
Secondly, Tsuna is more mobile than Absol given his flight and peak performance characteristic of his hard flames. Additionally, he also has ranged attacks, something that Absol is lacking in. Tsuna doesn't have to necessarily get close.
Even with statistics amp, which is the main thing keeping Absol in the running as Tsuna resists or bypasses most of Absol's other stuff, statistics amp will only mean so much if Absol finds it difficult to land a hit on Tsuna in the first place. It's simply that the hits that Absol does land, will count more than Tsuna's.
Lastly, since Tsuna will likely assume Absol to be some insane box weapon, petrification is extremely viable. (I also can't recall whether or not things that hit his cloak become petrified). Furthermore, the harmony attribute of his sky flames allows him to bypass magic bounce, meaning that his petrification would work just fine. This is complicated by things like detect, but Absol still must get in close to do any real damage. With in complicated heavily by flight, petrification, and very long ranged attacks in the form of X-Burner.
Also, not sure if the extra IQ skills means copying skills, but in order for him to use one of Tsuna's skills, he would need to have the same flame attribute (under verse equalization), and there's no way of knowing what flame attribute Absol would have. (Though we could likely make good guesses).