We have in the past been deliberating over Beta or Delta for you. I think we can reach a conclusion on the matter by looking at what you say quite early in the video, how you were drawn to typology as it was a means of categorising people into different sorts and that this allowed you to belong to a group of people similar to yourself and different from others. This is a very Merry way of looking at things. Essentially, it is an appraisal of Ti and Fe, group belonging ordained by logical categories. As such, I don't think your value system could be Serious like Delta. Instead, Beta or Alpha would make more sense.
Further evidence of Fe valuing is in your focus on the 'right attitude', i.e. the emotions you bring with you to a job should change depending on the scenario you are working. You feel there is a certain amount of zeal and pep with which one should conduct oneself in the workplace which is quite different to the Fi valuer who tends to cling to however he or she feels regardless of the situation.
I want to address what Susan said in the above post about reflecting and thinking over one's past and future. It is true that both of you do this, yet I would say that you are an Ni lead while Susan is an Ne lead. This is because both of you are Intuition leading so your main focus will both about perceiving information from your imaginations. As intutive types, you will both use Ne and Ni for this purpose. However, the difference between one's leading and ignored function is essentially value (and temperament), which one you go with and which one doesn't tend to surface in your behaviour. Susan as an Ne lead is essentially a jumper, she focuses on exploring the multiple possibilities and as such, she has done a large variety of different things in her life. From watching your video, you seem like more of a lingerer than a jumper, you carry on wondering and doubting, continually thinking about what you did in the past and what you will do in the future without running with any particular option. This would be leading Ni.
I had already been considering Te as a vulnerable function when you were explaining your switch to biology from mechanical engineering due to the difficulty of the work. It makes sense for someone with Te PoLR to want to evade such a Te-centric discipline as Engineering. What confirmed this hunch came at the end when you brought up again (we had considered this same anecdote a while back) the supervisor of yours that continually criticised how you were doing things, which is textbook Te PoLR inflammation. In disagreement with Susan, I wouldn't say that you need someone to tell you how to approach your future career, (she would prefer that because she is Te valuing), instead I would say you need someone to come along and just say "right we're doing this!", providing an Se call to action that can shake you out of your deliberation.
In conclusion, I would say that your video provides a reasonably solid confirmation of IEI for your type. A positive of this is that if you are still considering a career in the armed forces, the Beta Pragmatist environment might not feel so oppressive as I had thought it would be when we still believed you were a Delta Humanitarian.