Yeah. Do more observation of yourself -and optionally others- while checking the theory -this theory, other theories, other people's observations on you- against that. You will never get anywhere otherwise.
No, you really need to spot things about yourself. It's ok if you let others do it first but you need to verify yourself. Otherwise you'll just continue bouncing around like you've been doing it for a while
The Reinins are even worse in terms of that, you will not get anywhere with grammatical analysis on them, you have to see your own thought processes that are never fully revealed from these written texts. Some Reinin dichotomies then do make sense to me but yeah, only if I ignore any external stereotyped manifestations and instead focus on the core concepts on how the thinking processes work. Other Reinin dichotomies still don't make sense, the ones where I cannot see such core concepts.
Eh, Irrationality is not about laziness or not taking anything seriously. I recommend you read Jung's concepts on Irrationality and Rationality. One thing's for sure tho', you are no EJ.
I don't want to get into stereotypes here but this does sound like some sort of introverted Si valuer, I can't say more than that.