PS3 Hard Drive and about Gran Turismo

Hi all

Without delays:
1 - When I replace the PS3 HD (for a new, bigger and formated HD) do I have to Download the firmware again!? How long will it take if so? I know that replacing it is piece of cake, but about the software, is there any problem or trick?

2 - I am really considering to buy Gran Turismo 4 (PS2 game) for my brand new PS3 (coming in April), since its a great game. HOWEVER I know that there is GTHD. Is that the same game, only on HD resolutions? Is it trully free? What about its size? I mean, 15 gigabytes demands at least one night of pure straight download on my 2mb connection. I kinda like GT4 since it is the same concept as GT2 for PS1: lots of cars (over 150) and tracks. If GTHD is the same game on high res and it is for free, well... I heard its only a demo, is that true? If so I will download it, but GT4 would be still on my list

3 - Bah since I'm already here, any words about a PS3 guitar hero? Any news also about if there is any chance of slipping out the PS2 version from Sony's blacklist and finally bring joy to PS3 owners? I mean, its a HUUGE blockbuster megahit for PS2, how come it not be ready for PS3 till now? They will "unlock" it for the PS3 right? RIGHT?

and thanks in advance