Question 1 and part of Question 2 answer.
Question 2: Some brands can let you recover without the CD. Acer is
one. The others I'm not sure. Refer to the manual. If you need the
Acer the manual, I will get back to you at night, or somebody can
just post up.
Question 3: If you reformat, yes. If you are doing a recovery, I
don't think so. However, a reformat and reinstall usually requires
the Windows CD, not just the recovery CD, as recovery CD don't
contain all the necessary files.