reply to op
Analysing potential technical support/resistance areas in any market is really just about looking fore the most likely areas where swing points may occur against the immediate prevailing price direction, but whatever tools you use to determine this, and whatever response price may make at such, you use you have to realise that;
a. It is not an exact science
b. You will never be able to identify all the areas at which every market turn results.
c. The analysis you complete in this respect is best viewed in context with the overall prevailing conditions of the instrument you are trading (ie is the instrument trending, strongly trending or ranging ?)...as you correctly say it is best to view this analysis in the light of general market sentiment (howsoever you detrmine that.)
Given the above, whatever tools you use to identify potential support/resistance, all you can do is asssess the graeter probability of such a market turn (howsoever temporary,) given the readings of these tools/studies (that may and probably should include price action itself and it's reaction to the potential support/resistance and may include volume etc...) at such areas of potential support/resistance.
Many times I see price turn at an area that I had not pre-identified as potential support/resistance and the only conclusion I can draw from this is that the methodology underpinning my analysis for determining such did, on that occassion not pick up such an area. On other occassions I have poptential support/resistance factor (s) pre-identified at which I would not act if price tests them as they do not fulfill the criteria of my trading edge.
Potential Support/Resistance analysis is not the holy grail but just another tool that can help us gain a trading edge....on it's own it is less useful than when combined with other factors that can indicate the greater probability. Just because a greater probability may be highlighted by a trading edge, doesn't mean that it will always play out, such is the nature of a trading edge.
In the example you give in your post of eurusd and gbpusd turning at exactly the same time as audusd with no visible reasons to suggest that this may happen could be because of the above and/or that these $ cross pairings can be highly correlated. Whatever the case the analysis you did on the audusd pairing and the one you traded resulted in a winning trade (although you make no reference as to whether it hit your target etc...) so why concern yourself with what happened on other pairings ?
Furthermore I really don't think that it is a question of deriving satisfaction or being frustrated by the resulting price action after you have acted on your trading edge (particularly on pairings/instruments that you were not involved in,) but of trying to remain dispassionate about your trading edge, trying to act at it with impunity and in so doing realising it's limitations. All of this involves the development of a robust psychological framework/skillset that can take years to enable you to consistently profit from your trading edge.
G/L
I'm interested in people's views on this observation relating to Price Action. As someone who follows PA closely it's became more apparent to me that a lot of price action is following market sentiment rather than support resistance etc. So for example I'll often be following a particular currency pair, say AUDUSD on a 15m or 1H chart and I'll see the price hit a support/resistance level, whilst forming a Pin and showing overbought/oversold on a CCI or RSI. Confluence on 3 counts I'll be thinking. The Price will then bounce as predicted and will turn a profit. I'll have that warm glow and self-satisfaction from seeing the price behave as it should and reacting correctly to the S/R level etc.
But my self satisfaction wanes when I then look at other currency pairs, say EURUSD and GBPUSD and see that the price has turned at exactly the same time, without the benefit of any S/R level or Pin bar etc and I'm left thinking that the reason the Price turned on AUDUSD had nothing to do with the S/R level, or Pin or CCI/RSI, but was just following the general market sentiment.... Anyone else as frustrated as I am?!