how are we going to use BTC Market's information in order to determine whether to buy more, sell more or hodl?
BitcoinMarkets Flair Δ is comprised of reddit users, generally emotional but react quickly to change in macro and news. The sentiment actually tracks *changes* in sentiment, meaning how many people switched from bullish to bearish (and vice-versa) in the past 24 hours. A high long percentage for example would indicate that people think we've reached a bottom, that we've broken out, that we've been dumping for too long, or some kind of macro-catalyst just came out.
OKCoin Elite Traders are the top 100 trader positions on OKCoin spot. This doesn't indicate how big each position is, but just whether the trader is long or short.
OKCoin Futures Position Ratio indicates position sizes for longs and shorts. A 30% vs 40% sentiment means there is 33% more short capital than long capital. This can be useful to predict potential short and long squeezes.
Bitfinex (24h) gives a quantitative measure of rolling longs/shorts on Bitfinex over the past 24 hours.
Whaleclub.co Top Traders indicates how many traders are long vs short on Whaleclub.co and filters to include only the top 100 traders over the past quarter. It does not take into account position sizes, similarly to the OKCoin Elite Traders sentiment indicator.
So this should give you a bird's eye view of where market participants stand and combined with price and trend data can be very useful in building accurate trade setups.
Surely, if you could accurately gather and report such information, then it could be another set of factors that BTC traders could consider when, how much and whether to take a position.
however, some of the data that you seem to be describing seems to be private in nature - I mean, how would you really know the various positions of individual traders, unless you were either hacking into the referred-to exchanges or if you had some kind of inside information from the exchanges that you were using outside of the financial privacy permissions of the "whales" who you were monitoring. In this regard, I would doubt that any top 100 "whale"/trader would consider it within his financial interest to have any others knowing or studying his particular positions as he takes them or while the positions are still open or even from a historical perspective, except to the extent that he may agree to release such trading secrets.