Allow me...
1, and 3 - it's a magical process in wich the caster finds the proper creature he wishes to bind, then makes a ritual to bind his soul with the creature. It's not an easy task, and as said, you bind your soul with the creature. Like this, the little no-more-animal becomes part of you, as you become part of him. He grow in strenght with your strenght, he can feel your emotions, and he evens gains a personality to match with yours. Are you a person that needs some attention? Hel will be that. Are you the cold guy who makes inpact phrases? He will be your target. A familiar is like a best friend/part of you all into one...
2 - They are magical beasts. The body is of an animal, but the soul is part of your own.
4 - That's tought. Let's say that isn't so much in the practical terms. It might seems just the same: The two are close companions that grow stronger with you. The GREATEST difference is the LEVEL of connection. The arcane-familiar connection is much stronger, as such that the familiar can feel the master and his emotions, and the master suffers a great shock of pain and magical backlash (without speaking of psichological...) if the familiar even dies, and he gets weaker. He must wait much time to summon another one, as his soul rebuilds itself. It's like losing a brother... The animal companion is a loyal servant that is granted to you by the divine powers, like the paladin's mount. He is not part of you. There are even the legendary animals, that sprout in existence when a arch-druid needs an animal companion...
5 - In the server? I can't awser that.
6 - Because people seem to don't respect them and treat them as one more summoned creature? My character is a fighter mage, and he KNOWS that his familiar is weaker than many others mage's, so, he DOES NOT summons his panther for battle, because je knows that this best friend of him would be at risk. He summons her when he wants to speak with someone, when he feels alone, and when he just want a warm and nice friend to sleep with, to keep him warm in a forest... Familiar rocks, people should just RP that somewhat a little more!
