You can stop at 2, as the other 'options' are just slash and burn/scorched earth policies that will end badly for those foolhardy enough to believe in them. Most rational players will want to conserve whatever value they have put into bitcoin and are unlikely to be as petulant as the core devs will be. They will follow the longest valid chain.
Changing the POW is just empty sabre rattling from a dev who is seriously worried that this is getting away from him.
Agree they are unlikely possibilities (although not completely off the table because some of us, really , really do not want a paypal 2.0 and will make great sacrifices in order to insure this doesn't happen) which is why I suggested this more likely attack vector :
I don't believe you have really thought things through with regards to the possible attack vectors that large btc holders can have. First of all a 51% attack created by 75% of the hashing fork cannot steal individuals coins that are not being spent on the minority chain and the hashing majority has no idea which wallets are friend or foe. Large bagholders (almost all the core team and early crypto-anarchists who tend to prefer conservative implementations that prioritize security and privacy above mainstream adoption) can carry out some pretty nasty attacks where they can quickly devalue the chain with the most hashing power scaring all the miners to support their chain or they can simply quickly and secretly buy up mining farms and ASIC's and attack the main chain without risking any of their investments.
In fact, this course is a much more likely course that could occur over them changing the PoW algo.
The question one must ask , is who really is indeed the greatest economic majority?
The news that f2pool doesn't care for Classic. That Bitfury was just bluffing and is meeting Core this weekend.
Some sort of compromise is being worked out that would lead to a 2MB hard fork in........ Feb/Mar 2017.
Yes, I was wondering about that when I read Bitfury's post which appeared to contradict all the principles of Bitcoin Classic.
From Cointelegraph article, 7/2015 back regarding prior blocksize debate
http://cointelegraph.com/news/114776/knc-miner-slush-pool-bitfury-at-odds-over-block-size-increaseBitFury
Unfortunately, the biggest Western mining pool – BitFury - did not respond to CoinTelegraph's inquiry regarding the block size limit. According to Bitcoin Core developer Jeff Garzik, however, the Dutch-American pool that accounts for some 13% of hash power on the Bitcoin network is conservative as it comes to raising this limit. Garzik, who knows the team behind BitFury from several Bitcoin conferences*, said on IRC that BitFury is willing to raise the maximum block size to 2 MB, but not much more.
On the IRC channel for Bitcoin development, #bitcoin-dev, Garzik commented:
“Just heard from the BitFury guys – they are pro-conservative. [...] 2 MB is ok, more is potentially worrisome. [That in] contrast with [Chinese] suggestion [for] 8 MB.”
Given the fact that Classic has essentially issued an ultimatum, is it safe to say that, the 'gloves are off' and they have no choice but to attempt a fork?
Regardless of whether core decides to make changes can classic implement changes faster? It seems like a game of chicken that needs an ending