Hi, I joined when I saw this thread so I could contribute. (I also read through the thread hoping you've reached a final conclusion)
The process may never come to closure!
I'm a 20 y.o. ISTP and I'm studying product design
You must know how things tick.
To help you out, these thing happen to me often, and I think they're telltale of my type:
Ok, let's break these down:
-I say "Do you smell/hear/see that?" when outside with a group of friends because I smelled/heard/saw something without conscious effort.
I can't notice minute details in my surrounding worth crap, at least in comparison to how much my other friends/family see.
-Imperfections in things leap out at you (slightly crooked line, misalignment, something off, grammar, a stain on clothes and such)
Well, I guess I am something of a perfectionist, but it's more along the lines of maximizing conceptual achievement, rather than outward order.
-I've
been called emotionless and cold (note the called, I certainly am not emotionless or cold)
Ya, I can look this way too, that is, if I'm not interested in something, or if I haven't adapted to the setting; if I am though, I can be very energized.
-often I can sense when a machine is 'suffering' (not working as it should)
My dad is an ENTP 3w4 mechanic, and when I work with him, I fail to see how anything operates; I always have to be given direction.
Oh boy, childhood always brings out our pure and true selves!
-took stuff apart AND put it back together for fun. (And still do this sometimes)
Ya, I took things apart too, but I could never put them back together.
-played with LEGOs a lot. Alone.
Same with me too man, same with me - so many forms to be realized!
-tried building a better firecracker by taking the gunpowder out of several and mixing it into one
I'm too chicken to perform a risk like this, at least a physical one (I will take on 'anyone' though in an argument).
-built several working RC models of my own design
But I don't even know what an RC model is!
-rode my bike over every terrain I could as fast as I could (including downstairs)
Oh I rode my bike plenty of times, and pretty fast too, but never to the point where I could lose control; well, maybe a few times, but not too much.
Now, this is me, and I'm not saying you had to have done these exact things, but ISTPs I know have done something in this fashion.
All in all, I believe I have at least some of the traits you described in yourself, albeit to a lesser extent - but I have some traits of those nonetheless.
Hope this helps
Indeed, a crazy guy like me needs lots of help (And by the way, I'm glad my presence on this forum encouraged you to step in).