But, what about the camera showing nothing but blue ?

Here is a thread about fixing the USB port. It has some very helpful links in the first post, including to where on the board you can find alternative soldering pads.

Sorry, I can't help with the camera. Your USB port is your primary concern now: fix it and reflash, that may fix other things including the camera. If jot, you may need to look for a suitable hardware replacement.

Yes you're right, let's focus on USB then LCD and then all the not nessecary parts.

So, I'll order
-µUSB jack
-Battery
then:
-New LCD
eventually:
-New Digitizer
-New housing
-Screen protector

Two more questions :
How does the N900 lock ?
(as when I slide the... slider, It locks the digitizer but the lcd is still bright)

Is this slider that useful ?
I really want to make the mod with normal size USB but that the thing that prevent me...

For me with rather large hands the slider always was useless. Before my fingernail found the little knob of the slider, i could easier slide out the keyboard or hit the power button.

I have seen cheap non-branded ones on ebay - might be interested in buying one as well. Are they any good? Original Nokia's are still for sale but quite expensive.

Well, we'll soon now, I'll first contact the sellers to check the seriousness.

That what I was thinking, the poor slider will maybe be replaced by a USB then.

I use the slider every time i use the phone...

Nazmi: by default it will turn off the display.

Thanks, I'll rethink about it then...