But does every country in the world have the technology to reboot the system in a few days?
Of course not all but the first world countries have for sure the technology to not prolong the disruption if ever this phenomena happens.
Bitcoin blockchain is operated throughout the world. There will be many places that won't have access to the internet or electricity for many days.
The good thing is that miners are scattered all over the world, we will never know on which part is everyone located but on those countries that will be resilient on this event probably have some miners to work on it.
How will it affect the others who will get access to the internet and also to Bitcoin first?
IMO, not that much. There's no problem if someone gets to access first or last after this solar superstorm or any disruption that happens.
Also, not being able to use Bitcoin because of this could lead people to think that it is not the best thing to use. Will this fade away like what happens to most of the FUDs or it will continue to impact Bitcoin in the future as well?
It's proven that Bitcoin has always recovered no matter what the situation is.
Also, those who will not have access to it while others will have, won't they lose hope in Bitcoin? Because the price could fall drastically if people who get access to it first start to sell?
If those people panic and they put it on sell because they think the price have fallen, the others won't have access by that time so there's no volume yet. Although this can be a real thing, I don't think that everyone is going to lose hope in Bitcoin. We've seen the best and bad times with it.