1) You should know that if you understand the first bit about microprocessors.
They KEEP RUNNING, until tou turn them off. sjmp $ will lock the CPU up in a tight loop, setting IDLE will switch the CPU off.

2) Yes. So? You need the highest 8 bits. If I tell you to round off the number "6.4", would you tell me "4"?

3) You should study Michael's e-mail and take his advices to heart.

4) What is a thx? wasn't that a movie?