Basic pet questions

Since they're on sale today, I thought maybe I'd get a pet for looting. But I really don't know much about pets, and the "all about pets" guide seems to assume a lot of prior knowledge (or maybe I'm just too dense to understand it).

Anyway, my first questions are:

1) Is there any functional difference between different pets, in terms of looting? A pet that is described as "less obedient" will loot less reliably, or something?

All pets loot and autopot the same. Obedience affects closeness only.

2) What does pet level and/or closeness do? Does a pet with higher closeness range farther in search of loot? Does a higher level pet get hungry less often?

A pet whose fullness reaches nil will go to its house. That means it will not autopot you or loot for you. If that happens during Zakum or Horntail, you will probably die. So you need to carry around about 200 pet food and hotkey it for when it gets hungry. A pet loses fullness at a constant pace.

Closeness "function" is to have more things to say, and unlock more commands. Cloy in Henesys has commands for all pets, and pet merchants sell command books that you can carry around. at lvl 10 and lvl 20 new commands are unlocked. At lvl 15 a pet can be made to say things using /pet message. ALSO at lvls 15 and 30, your pet gains the ability to upgrade cheap, bad iTCG items to higher lvl items. That is significant because a lvl 80 iTCG bow has the power of a Metus with the requirements of an Arund; very very few people have lvl 30 pets, so it's a good source of money.

Lvl 1 commands are obeyed the easiest, lvl 10 commands less easy, and lvl 20 commands are hard to get off. The more obedient the pet, the easier it will obey. Increased lvl also makes it more likely that a pet will obey. The beauty of the porcupine is it's obedient as hell even at lvl 1, and its commands increase in potency as it levels. So, iloveyou gives 1 closeness at lvl 1, and 2 closeness at lvl 10. Not all pets are like that.

If you want a "great" pet, get the crystal rudolph. It is a Cash Shop pet which has a +3 closeness command. The orange, ordinary Rudolph has a lvl 1 +2 command, which makes it easy to train as well.

3) Do pets in themselves (not being equipped with meso magnet or potion pouch or whatever) have any purpose other than amusement/decoration? Do you get exp for training them, for example?

No, you need to have pet equips for the other stuffs.

4) I understand that your pet will only pick up drops from your own kills (not party members or strangers), unless equipped with Magic Scales. Correct?

You need that one Cash Shop item which lets you pick up others' items as their ownership over them expires.

5) Is it true the pet will only pick up drops I've walked over? So for instance if I am standing on the MP3 Hummer and spamming Arrow Rain or Heal or w/e, I will still need to jump down every once in a while and take a quick dash through the sea of drops, for my pet to pick them up?

Thanks!

One of the pet equips makes your pet run around to items; another pet equip INCREASES the range which the pet runs around at.