Re: 100% availability?
Can't tell you about the others, but online banking and ATMs certainly don't come with a 100% availability. There are maintenance windows and just general failure from time to time.
Users may *expect* 100% but the reality is very different. Highly available services (the stuff you don't want failing, ever) is only usually rated to what was previously the holy grail of "five 9's" (or 99.999%), which equates to about 5 minutes outage per year as I recall.
There's also the question of whether availability even means anything. It's a very crude tool to measure outage impact. A 30 minute outage on the ATM network is more costly to a bank at 5pm than 4am, but availaiblity stats will show the same figure.