Macbook and USB/Firewire Connections + Audio Interf. + Controller

Hey people, this is my third post at the forum, but I read it every day since november/2008.
I didn't started out my Digital Djing "Adventure" but I'm very close to. At the moment I'm saving some cash to buy my equipment, since I'm from Brazil it's taking a while because of the high taxes plus low equipment diversity we have here that put the prices even higher.
I have some questions to start buying my equip:
1) Are the second USB connection of the Macbook a Hub from the first or the two are independent ones?
2) If they are Hubs, Can I have any problem with latency or anything if I use an USB controller together with an USB Audio Interface? They will compete for the speed connection?
3) There is any difference between USBs of Macbook White 13'' or Macbook Aluminium 13'' or Macbook Pro Aluminium 17''?
4) Presonus Firebox and Saffire LE are similars? Whats the difference between these two Audio Interfaces? What is the price of both at USA?
5) I have heard from someone here at the forum that Saffire LE Hardware/Software doens't have an idependent headphone output to pré-listen the mixed music, is it right?
6) Traktor Pro Mappings will work with Traktor Duo? We will need any adaptations to the map works? Ean will support this version of traktor?
7) There will be any improvements to the traktor pro mappings for the 1.2 firmware? Is not affordable to me (from Brazil) to buy a VCI-100SE from DJ Tech Tools because of the high import taxes that i mention before.

Just for you to know, this is how it will cost to me here at Brazil for buying my setup: (in Brazilian currency)
R$ 3200 / 2.26 = USD$ 1416 Macbook White (old version, without NVidia new video card)
R$ 1490 / 2.26 = USD$ 660 VCI-100 Silver (firmware 1.2)
R$ 1500 / 2.26 = USD$ 664 Saffire LE or Presonus Firebox (aprox.)
R$ 600 / 2.26 = USD$ 266 Good Professional Headphones
--------
R$ 6800 / 2.26 = USD$ 3010

I think that is it. Sorry for the long post, but I really need these questions to invest so much money in this hobbie to become a professional.

Thanks for reading.

1) USB Ports are all dedicated ports.
2) When using a hub, this "could" happen however I heard of people having no problems when working on a powered USB-Hub as well.
3) Only difference I know of is that the 17" has one additional USB-Port- however, I can strongly advise you to buy a MB-Pro because of the Express-Card slot- that way you gain the ability to get another 2 USB-Slots with good latency!
Those are the topics I can comment on with expertise ;)

Thanks for your answers! :D

Still waiting the other ones :)

UP

please i still have my questions above and another one:

8) Somepeople are saying that the DICE-II chipset of some Audio Interface have some problems to do the job. Just search at the web and you will find a lot of threads of people complaining at home studio's forums. I wondering if these problems could happen with my setup?

Seems like the Saffire LE use a different chipset and for me, focusrite is a more professional trend then Presonus. They also are way much better with their drivers now.

I forgot to say that Presonus Firebox use the DICE-II chipset.