MGS3 Foxhound rank - any tips?

Hey all, been playing the games on console for years, got the Steam re-releases when they came out, and as of yesterday I have every achievement for MGS3...... except for the FOXHOUND one, attained by achieving the rank of 'Foxhound' at the end of the game.

To clarify, both for posterity and as a general reminder, attaining the Foxhound rank requires:

  • Beating the game on Extreme difficulty mode
  • Finishing the game in under five hours
  • Using 0 continues
  • Not killing anyone
  • Triggering no alerts
  • Use no Life Medicine
  • Taking less than 10 life bars worth of damage
  • Saving 25 or fewer times
  • And using zero special items (EZ Gun, Infinity facepaint, Stealth item, etc)

My current plan is to play through the game on Extreme difficulty at least once, playing normally but taking out the bosses nonlethally to get their special camos, as well as generally timing myself and practicing to see how fast I can get through the game total.

Once that's finished, I'm planning to start a replay with the unlocked camos in order to try and get the Foxhound rank. I'm anticipating a LOT of difficulty with this, so I'd appreciate any tips and advice anyone can give me.

For example:

  • Are there any instances of killing that 'don't count'? IE: if I tranq the hover-platform guards during the river section, and they fall and explode, that still counts as 'non-lethal', if I'm correct?
  • Is skipping the End possible? Only since I'm anticipating a LOT of time being wasted on trying to fight him non-lethally with only my tranq pistol and stun grenades (reminder: the tranq rifle is a reward for taking him down non-lethally). I'm assuming if I snipe him at the dock it'll count as a kill, but what if I use the time-skip method and he dies of old age? Is that still considered a 'kill'?
  • Related to the above, what parts are known for taking a lot of time to get through? I typically play slowly and patiently, and my play-times clock in as very long as a result. To that end, if I have to finish the game in under 5 hours, which areas are known for taking a lot of time? The ladder climb, the boss-fights, escaping the prison... anything I've missed that can really drag the play-time out? If I can get a rough list of these, I should be able to make up lost time in other areas, sprinting through empty zones to compensate and such.