it is common practice to separate questions in the forum, as they will otherwise be hard to search in the future. It would have been good if you had posted three topics instead of just one.
Anyway, your questions are very valid. I am happy you figured out about how to attach images in the playground, it is not the easiest thing in the world, but it is easy enough. The good news are that, unlike other places, we do not erase pictures unless they are offensive. Also we run backups daily and weekly.
As for the other two questions:
(2) An example is not so good at sizeof : http://arduino.cc/en/Reference/Sizeof
The last example should not have the "- 1".
Someone already mentioned this in the forum, but it is not corrected.
This is not exact. A properly formatted string is an array of bytes that has one more byte closing. That character is NULL (ASCII of value 0). Therefore we need one byte less than the size of the array of bytes that makes the string. You can try yourself to remove the "-1" from the code and you will see how character 14 comes out empty.
On the other hand, there was a different error due to the upgrade to Arduino 1.0 that removes Serial.print(var, BYTE) to become Serial.write(var). I have fixed that in the example, thanks for reporting.
As we noted prior to the release of Arduino 1.0, we are going to slowly let the ATmega8 go. There are many libraries that are not going to work with that processor because of its lack of memory space, but also because of having less timers. However, if there is a better library for tone that is also covering the ATmega8 I would like to know. Could you please post a link to the one you are referring to?