what is really sad is the fact that a company referred to as "large" or "top tier" which isn't in some irrelevant field but in the field of IT is being infected by something as simple as this malware and are the effects is considerably large enough to cause disruption in their whole system.

Blockcypher API includes the "sender's" address in its API response.
for example from the last block:
https://api.blockcypher.com/v1/btc/main/txs/499003ee50065a93bd786f792e3f72f99c8d308940fa1e5937178650a6a80fa2?limit=50

the "1ArgjWtWL8a2yshyeJUqtTtqgqKpZFGst5" is the sender's address. you will find each address in "inputs" list under "addresses" of that input.

ps. if the payment that you receive is important you may want to start running your own full node or at least an SPV node instead of relying on centralized services such as blockchain APIs.

well the good news is that when the business that is hacked is very little known you can be sure that it has no effects on anything regarding the market. we saw the biggest altcoin exchange (binance) be hacked and that didn't affect the bitcoin price one bit.
in any case i am always skeptical about these hack stories anyways. many of these stories are actually the failed business trying to make some money with little effort and there is nobody to look into them either.

everyone knows that the most profit is always coming from bitcoin but only to day traders and long term investors. those who look at short term charts can see losses at times.
so lets take a closer look at these two markets:

1) 2020 bitcoin's 86% rise versus gold's 4%.
after the coronavirus scare and the market manipulation that everything dropped bitcoin went back up 86% while gold only went up 4%

2) the actual 1 year (past 365 days) bitcoin went up 112% while gold went up only 31%

3) in the past 5 years (from Gold's lowest price in the past decade, note that gold price was higher than this, i intentionally used the lowest gold price possible to get the maximum gold price rise) meaning from 2015 bitcoin has gone up 13100% while gold has only gone up 48%.

if anyone is frustrated with these returns and think for a second that gold is leaving bitcoin behind then they are doing it wrong!!!

there were a lot of ICOs for literary any topic you can think of because that is the only way they could scam people out of their money. but not any of them did anything though, the only thing an ICO does is producing useless tokens and no matter how many of them there are, they won't change a thing in the world.

when some company removes something from one of their platforms we can't really judge it without having more information about what they removed. whether it is Youtube removing videos or google removing browser extensions, or anything else.
people usually jump to conclusions too fast. of course we had a lot of malicious extensions and if the removed ones were among them then it was an excellent move and long overdue.
it is like the Youtube videos, to this day i have not seen any valuable video be removed. only the crappy scam ones are being deleted.

fluctuations and volatility is not about control or lack of it. it is all about the size of the market. you can understand this by simply comparing two markets that you have  definitely seend. bitcoin and a small altcoin with daily volume of less than $500. the bitcoin market (big market in this example) can not be manipulated if you have $2000 but you can easily manipulate that altcoin.
volume is only one indicator, the other more important one is how packed the order books are. in bitcoin we still don't have full enough order books to be able to resist manipulations and panic buys/sells. that is why we see giant price rises and falls during scary times!

by zoom i mean looking at the charts for at least a couple of years instead of looking at them for a couple of months.

i am not an American but i did exactly that with the money that i received a while ago due to Coronavirus from my government. i mean why not? it is an excellent opportunity to buy something valuable at a big discount and right before its take off.
and that is not even considering the fact that the governments around the world are printing a shit ton of money these days that would decrease the value of fiat hence increase the value of bitcoin against it!
that to me is a no brainer.

the halving hype is definitely there and every day it is growing even bigger as more people are anxious to buy bitcoin expecting the hyped up rise. when you think about it, with the recent drop a lot of investors panic sold their bitcoins and now they are left with a lot of money that they are waiting to put back into bitcoin (buy back). everything is pointing towards a big rise since the potential is there. but the only thing that is not clear is the time of it. it could be pre-halving or a week after halving.

no there is nothing you can do about it. bitcoin transactions are irreversible so they sent coins not be unsent. and there is no centralization to want to judge the correctness of the accusations and "flag" the address as belonging to a thief.

bitcoin being strong or not and growing or not should always be about its network and its adoption and not its price. bitcoin is strong and growing because the security of it is increasing every day and on top of that the adoption is growing non stop even during the FUD season.
otherwise the price is going to continue fluctuating as long as the market size is small. but whenever we zoom out we will always see growth in price too.

you are looking at the size of the drop instead of also taking into consideration the duration of the drop.
you see dumping bitcoin price is not a hard thing. on any exchange a large sell off can easily cause a very big drop. 40% is tiny in comparison. it can be dropped down to $100 or less. but the important part is if it could last there.
because exchanges are scams waiting to happen, a lot of traders stay away from them as often as they can. so when a drop happens it takes time for them to go buy the cheap coins. if you look at the recent drop you can see that the $3800 didn't last at all. as soon as traders go the whiff of the drop they rushed to buy it and price jumped back up. so in fact the recent drop that bitcoin had was only from $9k to $7k or about 22%.
in short there weren't that big a selling pressure, there was only a sudden panic sell that was most probably a whale manipulation.

that is a different question than why bitcoin has value though.
"how much price" is mainly related to the supply and demand and also the way the market works.
i believe that bitcoin will continue to rise because as i said it is very useful and as its is adopted by more people the demand increases and with the limited supply price will continue to rise until we reach mass adoption.

ps. those who call bitcoin a bubble are either referring to a very short amount of time such as last month of 2017 that price did actually enter a big bubble in which case it is only true for that period.
or they are trying to spread FUD and scare other people.

mastering bitcoin will cover the technical parts and you will get the answer to most of your questions about mining, reward, confirmation and cryptography behind bitcoin. reading the introduction and how bitcoin works chapters should get you started.

but some questions such as "why does bitcoin have value" is not easy to answer and i don't think i've seen it anywhere. basically the reason is because bitcoin has utilities that are well needed. the ability to transfer money from one place to another around the globe in matter of seconds by paying a miniscule fee and without needing any middle man such as banks is worth a lot.

mastering bitcoin is all about the technical aspect of bitcoin (keys, addresses, network, cryptography, security,...). OP seems to be looking for the economical aspect of bitcoin though according to the book he linked.

halving takes place in a month from now! what are you live casting now? is it a continues "live" broadcast for a month lol

the whales have been accumulating for the entire past month. people don't want to talk about it but all those big withdrawals that keep getting out of exchanges is exactly whales transferring the cheaply bought bitcoins to their cold wallets

this was mostly report of some gloomy incidents in bitcoin and some of them weren't really that significant or even untrue. there were a lot more news about bitcoin in the first quarter of 2020. for example the French news about adopting bitcoin as a legal way of payment or the Indian government ordering banks to loosen their grip on their customers regarding bitcoin trading and some more positive news which were more significant than COVID, altcoins or some whale moving coins.

looks to me more like FUD specially coming from cointelegraph that is known to do these things. the market has been getting more calm and price has been rising back up again so that is scaring a lot of people who sold too late and now are in a big loss since they haven't yet bought back thinking price could go lower!

all true, and here is another one that people stopped talking about.
there is a lot of coins being withdrawn from exchanges to whale wallets. during the past weeks that bitcoin was being sold at a big discount anybody who knows better specifically the whales have been filling their cold storages with bitcoin by buying it cheap.

you are asking about one of the biggest challenges that any peer to peer network faces, which is the "initial" peer discovery. as it was mentioned it is by hardcoded seeders. the problem is that any P2P client has to know at least one IP address of another peer on that network to start its connection. to do that we have these seeders. but as soon as that first connection is made the client is already a part of the network and can find nearly all other peers by communicating with some of them and asking them for a list of other peers (their IP addresses) and by storing them locally the client can connect to those other peers in the future.