1. I'm pretty sure it sorts it automatically by semester, quarter, etc. It helps though to have a system when you put them in so you don't miss something. I STRONGLY suggest you get an official copy of your transcript and just start going down the list, making sure things match up. It can only help when it comes to getting verified.
2. Focus more on clinical ECs, service to others, research, and those to which you have dedicated the most time. Adcoms want to see your dedication, humanitarian spirit, inquisitive nature, and especially that you have "smelled patients." (Thanks
LizzyM!) Also, to save space, many people group all their honors together under one heading. For example, dean's list, an undergrad scholarship, honor societies, and an award in your major would all get one heading. If you won something national and truly prestigious in scope (like a Fulbright or Goldwater), then by all means give it its own slot. Save one space for a unique experience that every other premed won't have on his or her application. You would like to stand out from the pack like these people:
http://forums.studentdoctor.net/showthread.php?t=298508
