When you grow up, what kind of people do you find should not be deeply involved with?

It's simple—if someone makes you feel uncomfortable, just stop associating with them.
It has nothing to do with what kind of person they are specifically.
As long as being with them makes you feel that they carry a sense of superiority, ignorance yet arrogance, an attitude of arrogance and sharpness, behavior that is self-centered and extreme, speech that is subjective and biased.
And if you feel tired, have to cater, feel uneasy, restrained, fearful, lack boundaries and limits, constantly being treated as an emotional trash can, always blamed for mistakes, criticized, belittled, ignored, deceived, used, mocked, compared, discriminated against, disrespected, misunderstood, unappreciated, uncherished... If any of these points make you feel uncomfortable, or if you feel that your physical and mental well-being, privacy, interests, human rights, dignity, or personality are being violated, then you can consider whether to continue the relationship, let alone form a deep connection.
People worth forming a deep connection with are rare and hard to find. When interacting with others, don't expect deep bonds. Maintaining a mindset of a gentleman's friendship as淡如水 (as淡 as water) is a way of screening for good people, a form of cultivation and self-protection.