Quote: "1. what do i exactly need to make games using AppGameKit BASIC ?(not in native c++) ?. (my stationary pc = Icore 7 4 core 3.4 ghz, 8gbram, nvidia gt450, plus a labtop pc icore5, and a old Apple Mac Pro G5 dual core 2 ghz 2.5gbram, geforce 5200 agp.)."
Basically, you will need this:
Quote: "Intel Atom N450 1.66 ghz or higher Windows XP Service Pack 3, Windows Vista or Windows 7 1 GB RAM or higher OpenGL compatible graphics 1 gb free disk space"
Or either a Mac with those.
Quote: "2. can i just use a pc and AppGameKit to create games for Iphone ?."
Nope. You need a Mac & AppGameKit to create games for iPhone, because Apple made it possible to compile for their devices only using a Mac. (*sigh*)
Quote: "3, can i create games in AppGameKit for apple mac / pc, vice versa. ?"
Surely.
Though if you want a Mac game, you will need a Mac computer (PC cannot compile for Mac. Thanks Apple!).
Quote: "4. can i test the game, created in AppGameKit , directly on my iphone ?."
Yep. Though, you can use either AppGameKit Viewer which just copies the computer screen playing, and displays it on the device. OR you can use AppGameKit Player for iOS, but this will cost. Look at the Faq I guess. Should be mentioned there

(This will be 25$ (AGK Player service for iOS) + 99$ (Apple dev. registration))
Quote: "5. maybe its a god idea to pic up and learn objective C, but its properly damm diffcult ?."
Not a good choice. Go either with BASIC or C++, pick which one do you want. You should rely on your skills. If you have no experience with C++ (Or very slight experience) then go with BASIC. BASIC is powerful and it can create amazing things too. (Look @ Evochron which was made using DBPro - BASIC)
Quote: "what about support for 3D / opengl on iphones , using AppGameKit ?. (i would to create 3d games on iphone!)."
And as bjadams said, 3d is yet to come. I hope we will have it till the end of this year