It didn't burn straight through anything, it's just affecting the surface of the sand(that's how flames work actually) since the sand there is not compacted and it's mouldable.
It didn't just affect the surface; it burned straight through the sand. Notice the sand [
You must be registered for see links
] and then notice the [
You must be registered for see links
] The sand was even starting to melt.
Besides, he's manipulating enton , which can be launched and therefore, acquire some strength
Now this is where I know you're desperate. Enton is only the manipulation of Amaterasu; it allows Sasuke to control the shape of the flames, nothing more and nothing less. You're saying since he can throw it it's going to be stronger? Absolute bullshit. By you saying Enton is stronger since it can be thrown is saying it'll be stronger due to the fact that it'll have more speed than Amaterasu, which is absolutely retarded. The Enton projectiles move only as fast as any regular projectile would move: i.e.: his kunai, shuriken, paper bombs, etc. The only difference is that his projectiles are coated in Amaterasu via Enton. Amaterasu's velocity > the speed of projectiles, so your assumption that Enton is stronger since it can be thrown is plain retardation on your part.
Even if Gaara lacked the automatic shield, he would only be pushed by the launching effect, which is different from burning the sand instantly and making it dissapear. Once the sand layer becomes useless for defense , he would simply remove it from his body.
You're saying the same sand of a much lesser quantity is going to protect Gaara from an attack that already overwhelmed one of a higher quantity? :|...