So much trash immediately.
The obvious one is that telekinesis would only be considered the weakest skill in a world where the goddess nerfed it into being something that wouldn't be useful without several lifetimes of practice. Even then with the level of ability he already has, he could burst a vessel in his opponent's brain and let them die from a hemorrhage before they even knew anything happened.
Second, if it i so useless, why would anyone tempt fate by naming their child that similarly to the useless skill? But really this is just my hatred for lazy writing showing like naming a boy in a family of doctors Pharma for their pharmaceutical knowledge, or any plethora of characters with the ability to use light magic being named Light or it's synonyms.
Third, the hated and expelled half-sibling in a noble family is such an overused device that saying it is cliche is an understatement. It's a very convenient way to ostracize someone who hasn't had to struggle much in their first 10-15 years of life as the came from luxury that now they'll have to adapt. I'd much rather see the story of the ones that discover their abilities on their own as going to a priest for appraisal is an extravagance for the nobility since the blessings come from god not the priest. All they can do it tell you earlier than others would naturally find out their skills.
Don't get me wrong, I'm still going to read this slop, I'm just going to complain while I'm at it.