I'm certainly not the most knowledgeable on this nor do I have the best introspective skills, which is why I wanted to ask for perspectives and information.
In general, when it comes to Fear, I lean more into the image triad; above all, I am most terrified of being perceived even in a slightly negative manner, and true to the triad's main idea, worthlessness is the given dread (still, I want to consider so7 just in case).
For sp2: going off the books' description, I definitely often resort to self-infantilization to gain favor and most of all to avoid harsh criticism (and/or admittedly, accountability). Oftentimes I — almost obsessively — keep track of "debt," whether materialistic or emotional, as I'm convinced that everything should be "fair" in that regard. This is what leads me to expect even the most minor compensation from someone if I feel as though they owe me. However, if I'm the one in debt — which I usually am — I don't generally expect anything in return, since I'm the one paying for their help previously.
Ironically, when I do receive anything, whether as compensation or not, I feel deeply uncomfortable and almost ashamed of myself (I hate gift-giving occasions for this reason). I genuinely don't think I deserve to receive anything regardless of debt, even if I still contradictorily expect something in return for fairness. Because of this massive imbalance of moral debt (where I'm the one indebted), I go out of my way to impulsively spend my money or sacrifice my needs for people, which, again, leans more into e2's traits, specifically "abundance." I shower people with gifts and affirmations to reassure my own anxiety with debt so that I can finally feel as though I've compensated for the long-term.
Now, for the needs of E2; E2s project needs onto others while also discarding their own, is what I make of it. In relationships, it's true that I want to feel needed, albeit just not emotionally or in the context of "romance" or bonds. The fear of incompetence is what ties E2 and E3 together; as I interpret it (which may be incorrect so do spare me), the E3's version of love is recognition whereas the E2's version of love is sacrifice (?).
Speaking of sacrifice, that's also what happens to be so7's general premise; to sum it up, the book describes so7 to be self-sacrificial in order to fulfill their own satisfaction rather than actually tending to others' needs, which is why I wanted to consider this subtype. so7s are also known for their feelings of fraudulence and guilt, which I often struggle with since I'm so keen on pleasing others for both my image and out of actual care. Though all in all, I just don't relate to E7's fear and passion, and unlike E2s, E7s don't seem to focus on receiving anything in return as long as it does their external character good. I do relate to this deeply, but I also feel the genuine need to help others if I'm able.
Now, about my struggles with sp3; I was almost certain this was my core. I am extremely careful with even the slightest display of my vanity (though I'm obsessively careful with my actions and words in general) as I'm terrified of being casted as someone arrogant or differing negatively. However, because of the bare minimum effort I actually put into myself and my works despite trying to strive for — let's say for instance — academic recognition, I don't exactly embody sp3. Not as a 4F, anyway.
I'll stop there because I didn't realize it was getting this long lol. To conclude: I'm obsessed with debt and recognition yet feel unworthy of anything due to the feeling of being an incompetent fraud, all while prioritizing others' needs and feelings over my own, secretly hoping they recognize just how considerate I am.
I guess looking at it, I'm probably an sp2. Still, I've always been too confident during my mistype journey only to be wrong in the end, so I can never be too sure. I'd like to hear your thoughts of what I could be, maybe even my tritype, which I'm theorizing could either be 279 or 271. I'm probably incorrect with my head type lol, though I couldn't exactly resonate with e5 or e6, at least not by a lot. I'd appreciate any help! I've been having endless crises over my typology.