ISTps I've met

Hello, I've met some people in my life who I think are ISTps and they greatly interest me, so I'll try to describe them:

They look introverted, often interested in working with their hands.
Some of them can look irritated most of the time and can be rude when they see behaviors that they don't like.
Another type of them is often relaxed and calm and are often interested in physics, mathematics and are more outgoing than the first type.
They are very observant and notice every little detail. They often criticize.
They can be very kind and caring with their family, friends, or someone they find interesting.
They like to keep a large distance between them and others. Even if they value the person, they prefer if he's somehow far.
They can for example love someone without doing anything, only after years. If they want to keep that person they will find ways to not lose contact with them.
They can act apathetic when they're not, and this is often in moments when they are having a problem.
They often feel good when they're alone and they don't like long conversations.
They greatly value frienship and can feel lost and depressed if they had to part with someone precious to them.
They sometimes really regret their behaviors and care deeply but it's not really apparent to people.