Stephen
Despite my reservations about this system I had a look. You do not appear to be using Yahoo data, which is definitely wrong for its recording of highs and lows, and so the methodology is worth looking more closely at.
I disagree with you in your assertion that the opening is not important. For instance if the market opens above your target long entry then you have a choice. Either you go long at the open, or you record a no-trade and do nothing.
I re-worked your spreadsheet, using my data which I get from Sharescope. This does reflect the fact that the open does not match the close except in unusual circumstance, but as I have never traded based upon the open I would need to test whether this was in fact the case. I make the assumption that if the opening is higher or lower than your long entry or short entry points then the system goes long / short respectively at the market opening price.
The fact that you don't know, in a volatile day where both entry triggers are hit, which comes first, I figure is irrelevant, as clearly either trade would have been stopped out when the opposing trigger was hit.
I have also used a spread of 2 points for th DAX and FTSE and 4 points for the S&P and DOW. I have not allowed for any slippage, which would occur if you had to open a trade at the market opening, but would likely not if the order was a limit order.
To my surprise the system does seem to work on both the FTSE and the DAX, although not at all on the DOW and would work if the entries were reversed on the S&P. I have a niggling doubt though, so I've attached the spreadsheet for review and would be interested in whether anyone can spot any flaws.
Regards
Ben