I appreciate the great length that you have gone to in addressing this issue. However, please note, that just because one person does not correctly exegete a specific text, that in itself does not negate the system. I think you will acknowledge that most trinitarians do not even understand their own doctrine much less be able to exegete many of the texts which are used to support or deny their doctrine. Does that make sense?
The one error I saw in the above is the focus on ego eimi rather than o wn. Jehovah's name in the Septuagint is NOT ego eimi - that is simply a common phrase reading to identify something - which is the predicate nominative (often implicit but identifiable in the context cf Jn9:9 as noted). Therefore Jesus could not have been using ego eimi to identify himself as Jehovah.
This is further substantiated by John's use of o wn in Rev 1:4, etc.
Therefore, the issue remains - what is the implicit predicate nominative in v24, 28, 58? Well, it s/b pretty obvious because it is explicit in the context. I am certain you can identify it at the beginning of the context (which, btw, flows through Ch9 and is quite magnificent).