It takes him that long? What the hell deck is he playing? Or maybe he didnt pay enough attention to previous turns, already played cards and remaining cards in deck? 
I can think in only one situation it might take that long and thats Gala priest mirror in fatigue where you are trying to get the edge and guessing what cards might he have to punish you.
Yes and no is my guess. Part of “the show” is talking to twitch chat. I know when I get a call, or talking with family during a game etc. the odds of me roping increases.
and thats the reason hes top legend while you are gold 
you should try to actually take all options into consideration instead of just playing whatever first comes to mind and plan out your cards ahead. if you still manage to do it in 20s then you are doing something wrong.
its actually very easy to keep track with practice. based on your statement im guessing you are one of those players that complains that your opponent was lucky because he had a specific card when it infact sat in his hand for 10 turns before being played.
hand tracking in hearthstone is also much easier than in a physical card game since the cards positions are static in hand. at irl events in mtg or yugioh your opponent will constantly shuffle his hand to keep information hidden. many cheaters have been caught over the years because their opponent tracked their hand and could tell the judge the exact and that the fact that the opponent either lied on a previous turn or straightup cheated by activating card effects that wasnt legal because he lacked the correct cards in hand to activate it.
So here we are with personal unsupported claims? Well then…why not.
Im not gold at all.
Main difference on rank for average player is time spent than anything else either way. Maybe luck with win series, but in the new format I do not think its that important as it used to be.
No. I am just able to process the outcome and possibilites pretty fast. And I do not believe I am an exception.
No. I usually whine about rng - card A discovered from card B that was discovered from card C.
Something being easier doesnt mean its relevant or even reliable.
I understand your groundless subjective opinion. These are just completely in contrary to my opinions.
But do you see me telling you ,you are just thank kind of player that bootlick whatever some streamer say? No, because I am trying to present my opinions in more common approach. Kinda hard with subjective things but there is no need to actually push it in more emotional or personal way.
groundless as in 8 years of playing Yugioh at a high level, including many international events and multiple European Championships? Hand reading is a very important component if you wanna compete for the top spots instead of going x-3 and drop
To be honest, that kinda failed to impress me for some reason, let alone convince me.
You think its important, I think it might be useful (but still unreliable) in very limited specific matchups and even then in very specific situations.
In general I think its just guess. Same as thinking about what are the odds to draw specific cards in certain ammount of turns.
Very minor and unreliable addition to make me call it significant or relevant.
execpt the cards in hand isnt random once they have been there for a turn, you have alot of information based on what they played on their turn and you can from there determine what their hand is. you honeslty dont need to know 100% what every card is, its enough that you know that a priest with a 80% likelyhood has a mass removal in hand and you should therefore not blindly throw your entire hand onto the board. Similar you can determine that no card has been held for more than 1-2 turns making it much more unlikely a situation specific card is in hand.
every good and experienced player considers it important. the fact that you dont speaks more about your level than anything else
Taking it as control class based around removals might have removal on hand isnt that hard to predict. Same as it isnt hard to predict if aggro deck is holding certain card in hand it might be silence or finisher. You dont need any extensive hand tracking to take that into an account.
As I said - its a guess that can either heavily punish you or favor you if you play based on your assumptions.
Even when its groundless argument it might actually be true. On the other hand it might actually be wrong. Thats the way with purely subjective opinions.
This is subject to many variables, though, such as player-in-question’s experience with said deck, avrg. skill level, etc.