How can I change BTC into normal cash? Can you eventually hold the bitcoins in your hand, like real cash dollars or euros or something? If so, how?

I've gone through all the service previews and introduction videos (actually, a video), and didn't see anything about this particular point.

I don't have a credit card, and I'm in a country where banking services aren't so profound and  people don't use credit cards (Libya). Does a Bitcoin account rely on having a credit card, and will the coins you gather be added to your bank account?
Bitcoins are a purely electronic currency. If you want to sell them in exchange for dollars or euros, you can do that. But as Bitcoins, they exist purely electronically. There are physical Bitcoins but basically, they're just the key to an electronic account printed in some form.

I think you're missing the concept that Bitcoins act like a currency or commodity. You can have 10 Bitcoins just like you can have 10 ounces of gold. The key difference is that the Bitcoins exist electronically rather than phyiscally. If you have Bitcoins and want dollars, you have to find someone who has dollars and wants Bitcoins, then you exchange with them.

Bitcoins are not a payment or fund transfer system for national currencies like PayPal and Western Union are. Bitrcoins are a currency that has an efficient built-in transfer system.