I haven't been playing for too long, about 2 weeks, and my hunter is my first character that i got to 55. I need someone who has a lot of experience to answer this, and has created a death knight. What are the pros and cons? Is it worth it to give up my pal that i've had 2 days of game play with? Or should i get my hunter to 85, get more experience with the game, and wait to trade like a warrior or something?

Death Knights Are Awesome. But Ive never played a Hunter. DK's can fill tank or dps role, with buffs to dish out as well. they are also fairly easy to level as they can heal themselves. ultimately, it is entirely up to you.

i would, it helps to experience multiple characters

you don't 'trade' any characters. once you make your character, he is going to stay that class. you can have up to i believe 50 characters but unless you are illegally selling/buying an account you won't be trading any characters just starting new ones

You don't trade the character's.

The stipulation is simply that you must have played to level 55 at least once, before you are allowed to create a Death Knight, which starts at level 55.

This is just so you don't miss any content.

Your hunter will still be there if you decide you don't like the death knight, so just do whatever you want, you -are- paying for the game - make the most of enjoying it, or you're wasting your money.

There is no exchange. You can have both characters. Play one for a bit, switch to the other, then just go back and forth as you feel like it. You aren't giving up anything on your hunter by playing your DK. Your hunter will still be there exactly where you left him.