UPDATE: I've finally accomplished to successfully flash my eMMC and firmware. It appears that after leaving the device connected to the USB for a minute or so, after it looses the connection with the flasher while trying to boot the device into flash mode (as was described above), the device suddenly boots up again, going all the way to the maemo's "5 running dots" load screen, which freeze after a few seconds.
Flashing the eMMC is able to work when the dots freezes, so I successfully flashed my eMMC and then turned on to flash the device's firmware, which also went fine (it appears that the flasher won't 'lose' the connection with the device when flashing the firmware, as opposed to flashing the eMMC).
But yet, the device won't boot.
If I turn it on, it'll just do what I described in my first post on this thread (e.g going all the way to the screen with "Nokia" logo and white background, and then the screen fades out and the device is turned off).
If I connect it to the USB, it starts immediately as if I started it in flash mode (like I pressed 'u' when I connected it - which I didn't press), then quickly leaves flashing mode, stays lit for a few moments and then the screen fades out and the device is turned off - only now it does that in a loop, even if connected to the wall charger.

Any ideas anyone? Is my device finally dead?