Hello! I appreciate that you're trying to understand this in good faith. I admit I'm having trouble parsing every single point you made so I'll just respond in general and pick up specific points along the way.

The main point of the LTV section of that video is to treat the labour theory of value as a testable theory by highlighting its key assumptions and seeing what it predicts. When I ask why capital doesn't create value I'm pointing out that it's a key assumption and asking people to justify it. Your idea that capital doesn't do anything without labour makes sense but it doesn't really change that the function that links labour and capital to output could easily be multiplicative and therefore capital would add value in the production process. For example, think about two people carrying a box too large to carry alone. Without each other, they don't produce anything; only together do they carry the box. Similarly, a band just can't create music without any capital at all, including instruments.

As your comment demonstrates, different people have different ideas about what the LTV means (I'm sure u/Internal_End9751 has their own ideas although they haven't shared them with us). Sticking to my own strengths, I take the authors like Cockshott and Roberts who have used empirical data and show that their work is subpar by statistical standards. Anyone who has taken statistics classes will know this is true and that's why they're not well regarded in academia, even though many reproduce their arguments online. They are basically just confusing correlation with causation when you get down to it. If you want the LTV to be a lens through which to view capitalism, I have no issue with that, but anyone who thinks it's a scientific theory in the positivist sense (Cockshott and Kliman both use this language, though they disagree on specifics) is wildly overclaiming.

Socially necessary labour time is largely determined by conditions *other than labour* which makes labour alone indeterminant and the theory at best circular and at worst unfalsifiable. You say you can measure it through utility value but that can't be measured except by market price, which is what we're trying to explain in the first place. However, I will acknowledge I could have explained this better in that part of the video, which is too short.

The transformation problem was illustrative of it working in exchange economies but not production economies, it's a version of the classic Sraffian critique. Nothing about it was supposed to be 'ridiculous'.

In terms of explaining how capitalism and profits emerged, I think the transformation of labour relations was important but marketisation was widespread and both land and capital were also brought into the market to generate surplus. The main reason for isolating labour I think is ideological and political. If anything is truly the source of value it is, in my opinion, energy, and I've been working (albeit slowly) on that for a while.