this news actually sounds pretty great. i have not seen much details about this since it is mostly in the early stages but from what i have read in these articles so far, i believe this can help bitcoin's adoption a lot. it makes accepting bitcoin payments much easier and we know that convenience is a very important factor when it comes to merchants adopting bitcoin and users wanting to pay with it.

it is never the exchanges fault. so your question is kind of strange asking which exchange is best.
it usually is the fault of the user where they put a false address in their withdrawal or have some kind of malware on their computer that causes things like this or even have malicious software instead of a legit bitcoin wallet!

it depends on what you are trying to avoid but generally i can say:
keep your computer clean!

RDD is one of those coins that gives you the PoS reward thing and it has a nearly stable price which means it can be a decent investment if you want a small profit on it over time and if you are staking.

but the best profit is only when it gets pumped because the price of RDD is pretty low, any pump will be a very huge profit. right now i see little hype about it which means it can be a potential investment soon.

what are these "many" sites that are doing this?
i have never encountered any of them except for hearing news like what OP shared! and don't forget that if they hide it, their reputation is ruined in less than a day because browser mining with a lot of pressure on the CPU is not something you can hide and even if the pressure is low it won't stay hidden for long. someone will eventually find it and that only takes an hour on popular sites and a little longer on smaller ones.

as many times as it was also forked in the past. the numbers are countless as a matter of fact. the biggest one to this date was bitcoin cash and it was only big because they made a lot of "noise"


why?
each time they fork bitcoin they do 2 things:
1. give free money to bitcoin holders
2. prove what consensus of the majority means when their fork never goes anywhere after a year.

sadly that is not the number of transactions that people make as "payment". that number is a lot smaller. that is mostly people transferring bitcoin to exchanges, gambling and lots of other things.

most of the merchants use services like Bitpay and that has no "maintenance cost"

first of all you bought in the bubble. price went from $4 up after all!

secondly you don't move from xyz to bitcoin. lol. you should already have bitcoin and then have some of that bitcoin in xyz for profit. here in LTC while it was rising and then pull out back to bitcoin and then invest in the next altcoin then pull out back to bitcoin and so on.

* bitcoin is a currency
* ETH is a useless token

* bitcoin is the most secure cryptocurrency ever. be it the code or the network
* Ethereum is the worst cryptocurrency and least secure out of all altcoins. it has already been hacked, the official wallet hacked, the smart contract abused multiple times, people lost multi millions of dollars.

* bitcoin is what everyone knows about and trusts, the merchants adopted bitcoin. investors see bitcoin as a solid investment. if you go out in the street and ask people if they heard about bitcoin or ethereum there is nobody who has ever heard of ETH and not bitcoin first.
* eth has no usage. it is only abused by the ICO people to create new ICOs and most of ICOs we already know are crap. there may be 1 or 2 that try to do something but the rest ....

* bitcoin has been performing seamlessly for as long as it was around (8-9 years) and never failed even a second to not work or the network to go down or anything like that.
* ethereum has already failed a couple of times to handle a simple surge of transactions

* bitcoin had no premine
* right now even after this much new ETH mined there is still 80% of it premined

* bitcoin is decentralized
* eth is greatly centralized.

smart contract is already coming to ETH. so if we all agree that you are correct then as soon as smart contracts come to bitcoin (in a couple of months) ETH should die.

i believe this has been discussed multiple times already to somehow use DNA with private keys or something like that. each time the topics discuss similar or different things. do a little search.
a couple examples:
https://bitcointalk.org/index.php?topic=695568.0
https://bitcointalk.org/index.php?topic=234010.0
there are a couple more with better discussions, but i couldn't find them. give it a try yourself.

bitcoin: for obvious reasons.
Byteball: because of DAG
Monero: because it is the anon coin

the rest of altcoins are my favorite in terms of profit.
ethereum: it is THE pump and dump symbol
litecoin: brother to bitcoin and moves up with it
ETC: because it is defying ETH and its pumps are always good.
BTX(bitcore): because it has a solid rise which seems to be increasing in long term.

i sense another pump and dump is coming to ethereum.
it may even be some very quick and small pump and dump to make some money out of it but it will be an exit strategy because of the fear of hard fork and that can cause a lot of issues with the price of ETH.

the only thing coming out of it is money if you can catch the pumping part of the duo and also the fact that ETH will go back to its real low price.

nobody can possibly tell you "how much"! because it depends on you and how much money you have and how much of it are you willing to invest.
maybe you are rich and your starting amount can be 1 million dollar.
or maybe you are poor and can only invest 20 bucks.
or in the middle

what matters is that you first learn about bitcoin, then understand the risks involving your investment and then invest what you can afford to lose.

it depends on whether you are solo mining or mining with a pool.
in solo mining, if you find a block you get the whole reward of that block. right now it is 12.5BTC and there is always fees which can be small or big up to 4BTC even.
now the question is how much hashpower you have and how many blocks can you find per day if any with that hashpower.

if you mine with a pool, you are sharing the work so you share the reward also. and depending on how much work you do, you get a part of that reward. for example 10% of the total. but you also usually pay a fee to the pool owner.

i will only believe this when i see Chinese trading volume goes to actual zero. until that day they are in the game with the same strength as before (it was not as big as they showed it on the media but it was big enough).

and so far the volume is not actual zero. there is a lot of activity coming from China. did you know that bitcoin price is so much lower over there? and people are on a buying frenzy? on top of it there is always localbitcoins and others where they keep trading bitcoin on.

centralizing an altcoin means the death of it!
you can create a centralized altcoin like ethereum and hide the fact pretty well and fool everyone into believing it is otherwise, but if you publicly and foolishly make it centralized by even having the name centralized (bitcoin china) you will be killing it with your own hands.

burger king also has a cryptocurrency associated with it. it is something like burger coin and it is not worth squat.

YES obviously!

so far those coins/ICOs with the best advertising team and lots of marketing have been more successful than anything else. the examples among actual coins are countless.

there are a lot of shitcoins with good advertisement and good pumpers that are on top. and there are good coins that are doing the same thing better than those same shitcoins but they lack advertisement an they are on the bottom and nobody even hears about them.

as far as i know Copay is just a wallet and it has nothing to do with their "merchant interface" options. and this wallet added support for Bitcoin Cash. and that has been because the users who are either using Copay or those who are supporting BCH have been spamming them for support of this coin.

so far i have not seen any merchants though.
if they start then that will be worth mentioning because it will be big.

i have actually seen the same thing in other markets too. the news always affects the price. for example some natural disaster (i think it was flood) caused a big increase in HDD prices because the manufacturer was in that country!

the thing is, when the market is small and full of panic sellers, the news can affect it a lot. but when it becomes bigger, lets say something like Forex, USD price won't tank 50% in a week just because of some news but it certainly drops a lot because of some stuff.

diversification is a good thing but you should diversify your money into solid investments. use bitcoin plus stocks, gold,.... or things you find valuable investments. don't just focus 100% on cryptocurrency markets. that's my approach anyways.

and as far as altcoins go i am not a fan of investing in many of them. i tend to have only a handful to be able to watch them more closely. they can give you good profit but their profitability time is often short.
during bitcoin bull runs the bitcoin market may attract most of the attention and money anyways so altcoins may not be able to get the same attention.

probably around the old stable price of $10 and at best at twice that meaning $20. and it will eventually head towards that. there a couple of blocks in from of it which when removed will help the drop greatly.

one of them is the mining and all the miners who have been supporters. when they kill mining ETH all these supporters will also be killed and one big resistance will be removed.

the other one which is even bigger is the ICOs which will eventually come to an stop and there will no longer be this many of them. by that time there will be no more demand for ETH and that is another big resistance removed.