I am holding on to the opinion that the shot(#29) of R&A is in the London underground because the aluminum framed poster behind Rob looks like a "mind the gap” reminder.
As they say in the NFL: "Upon further review" we find that you are right, this is a shot of Amber and Rob at an Underground Station and that is a poster for the Mind the Gap campaign. They are wearing the same stuff they had on when we saw them walking through the airport, so this may be them buying tickets to take the Stansted Express into London, or more likely at the Underground station at Liverpool Station where the airport express would leave them. The thing that Amber is passing on to Rob looks like a ticket of some sort and you can barely make out the magnetic sripe that these tickets have nowadays. Hope they were smart enought to buy a Day Pass so that they can move rapidly through the turnstiles at other stations. Amber may also be asking directions of how to get to Abbey Road since the clerk seems to be sorting through some kind of papers.
We have been assuming that the first location of a clue box is at the Abbey Road crossing, but if the producers have reserved an early opening of the London Eye just for the TAR teams, this might be the first location. But since the clue about the Beatle's Album was included, I guess, with the instruction to fly to London which the teams got at the Pit Stop in Istanbul, I imagine that this is the first task to complete.
In regards to final three, which seems to include R/K because of the RaceyGirl picture of them "at the airport in Puerto Rico" I still have my doubts. If the team of R/K lost all of their stuff and money in Istanbul, would you be buying a new backpack for what little stuff you had just for the last leg of the race? This is because RaceyGirl's picture shows a shot of Ron with newer, smaller backpack. Very curious. Or just a good job of photoshop editing?