This might help you decide upon your type.
Naranjo: Character and Neurosis.
Since you seem to be seeking some external clarification, your explanations seem more like 5 with the influence of 3's id based drives than 8. Add in sx subtype, and you've got a cocktail for behaviors that may, at times, seem 8-like. However, Enneagram isn't based on qualifying behaviors being exhibited. It is based on core motivations. For 8's, that core motivation is the need to not be vulnerable. Ever. All of the extension motivations serve that end and are derived from it.
It is similar to 5's core motivation which is fear of the unknown, and thus avoid being a victim of the unknown, which can cause some confusion.
Your sig implies 539 sx. 359 Tritype
Enneagram: 9w8 - 5w6 - 3w4 sx/sp (Rearrange this, and you have 539.)
Self-confidence is knowing you're right. (Strongly implies 5's need to avoid being a victim of the unknown by being certain.)
Arrogance is thinking that being right makes you superior. (Implies 3's need to be admired but 9's need to harmonize.)
(The assertion in these statements implies an sx push.)
RCOE|I| (INTJs are most often 5's)
Lastly, I'm awarding you Necromancer of the Month for reactivating this thread, seeing as you're not an NF (Idealist). However, it was nice to revisit a moment when I thought I was a core 8, rather than a fix. Enneagram certainly has a learning curve.