The thread topic relates specifically to candlesticks only and nothing else, but it seems like the last pages are focused on price action - which may or may not involve candlesticks.
What is price action?
Simply price history reshaped however you like it, i.e., lookback period, bar type, bar interval, multi-time frame analysis, etc.
Can you trade profitably using only this information?
I certainly believe so.
However, that doesn't mean it's not possible to trade better using other/more information which can't be derived from a chart alone. But saying you can't trade from a chart alone seems arrogant and un-informed to me.