Your spelling & grammar are despicable, but I'm feeling generous today so I'll bite:
1. There are no BIOS mod chips. Only DVD-ROM firmware hacks and mod chips exist right now. That means you can make and run backup games, but unsigned (i.e. homebrew) software will not run on the 360 yet.
2. No. All Xbox 360 executables are signed with a different key for each type of medium they can be run from. That means demos you download from Xbox Live are signed with a key allowing them to be run off the hard drive. Full games are signed to run only from a DVD.
3. No 3rd-party hard disks have been known to work with the 360 yet.
4. Current firmware hacks cannot be detected by the DVD-ROM drive's own firmware read functions. If the CPU tries to ascertain the contents of the drive's firmware memory, the drive will give incorrect information to the CPU. That doesn't mean Microsoft won't implement an alternate method of detecting hacked Xboxes in the future. Use Xbox Live at your own risk.
5. If you study your history carefully, you'll know that later iterations of the original Xbox were more reliable, but also implemented better anti-hack mechanisms. Microsoft is slated to roll out with a new version of the Xbox 360 with CPU and GPU made from a 65nm fabrication process (compared with the current 90nm process) in February. Less power consumption, less heat output, less fan noise, possibly with an unhackable DVD-ROM drive. It's your choice whether to buy now or later.
6. Yes. Xbox 360 will work on standard definition TVs.
7. You're actually asking two different questions here. Firstly, you want to know if an Xbox 360 can output both NTSC and PAL video. This is important if, for example, you live in Canada and imported an Xbox 360 from Japan. Japan TVs accept PAL input and Canadian TVs accept NTSC. Can the Xbox 360 switch between the two?The answer is no.
Secondly, you want to know if Xbox 360 games are region-locked, and whether or not such region-locking is circumventable. This is important if you want locally-purchased games to work in your imported Xbox 360. Answer: not all games are region-locked. There is no way currently to circumvent region-locking for games that are locked.
I think that's all. My fingers hurt. Cheers

if i get one, it'll be pretty soon.
also, if i get the core system, i won't be able to save games right? does the console have any kind of storage, or do i need to get a memory card or the hdd?