People, start doing some research before you post here, this is getting out of hand...
Break SHA256
Really? That's your biggest concern? Of all the possible things that could ever go wrong with bitcoin, of all the attacks all the parties against bitcoin could do, of all the technical problems and unsolved scalability issues, of all these things you identify 2 most important, and one of them is breaking SHA256???
Where do I even start?
SHA256 and all the crypto used in bitcoin are industry-standard algorithms that have been tested by years and years of smartest people in the world trying to break them. They are used everywhere, in all the security mechanisms around the world.
Breaking SHA256 would cause must more problems to other projects, because if it was indeed broken (or any other crypto), it would be just simple to choose another algorithm and make a hard fork. It's not pretty but everyone in the community (especially all the miners) will switch to the new chain, since it will be required for safe operation. They have switched to differnet block size chains, just because core devs told them, you don't think that they will switch at once when there is a real big crypto problem?
Also why would you assume that of all the crypto used in bitcoin, SHA256 is somehow most vulnerable??
There are problems with legality status of exchanges and merchants accepting bitcoin, the ever-growing blockchain spam, security problems, bubbles, bad press, resource hogs, transaction spam risk, overall complexity of the system which makes it difficult for an averge joe to understand. There is mining centralization risk, exchange centralization, several attacks etc., and you think that SHA256 is the biggest threat...
