I doubt Gaara is afraid of Naruto.. but I think Naruto interests him alot now that he know they are pretty similar, and he might be curious about the fact that naruto can use kyubi chakara or have kyubi wihtout him beeing affected alot. Wich I think Gaara is alot by Shukaku cause he's posessed by it. I guess we gonna get more info on shukaku later on. But I doubt Gaara is in super control over whatever it is..