There are already THREE HUGE flashing stop signs that light up on the way to the tunnel if your truck is too big. The water sign is a last resort only.
It has explicit error handling (via multiple return values) which the authors argue is superior (even if more verbose) because they know from experience that programmers tend to make mistakes forgetting to check for errors in their code. If the error code comes back as a return value the programmer has to consciously decide what to do with it immediately, leading to better code on average.
Sure but that's not the point here. The important thing is that this quantum computer actually WORKS. In 2 years classical computers will be maybe 5 times faster. But this quantum computer will be 1000s of times faster (at these specific problems) so very soon any comparison will be irrelevant.
Bitcoin addresses are hashes, not the public keys themselves. Thus they are safe against a quantum factoring algorithm. If you spend money from a bitcoin address though, the public key does get written to the block chain but to combat this you merely have to send your change to a new address and you'll be safe again.
If the client is 'not worth it' you're just not charging enough. Just work out what your price is and send them a new quote. Don't ever fire a client, that's just silly. Make the client say no.
Every 10 minutes some coins are dropped in a big dark pool and everyone interested in catching them play hungry hungry hippos until some lucky person gets it.
Go on any Bitcoin forum and the newbie section will be filled with people wanting to buy Bitcoin with credit cards, usually via Paypal. Some of those will be scammers but not all of them.