Thank you very much for your advise, Biketool. The Nokia N900 sits perfectly in the tilted (and not very well designed, I admit) charger that I got. Despite it's quite slippery (specially when a dusty layer builds up in the rubber ring that it's supposed to hold devices in place), the N900 manages itself to be in good position held by the protuberance that surrounds the camera part.

I applied the software solution you pointed:
(I´ve got "CSSU testing" an "Kernel Power 52" installed, I think... not sure).

After that, both battery indicators (the 'system one' in the top left area, and another one battery widget I put in the main desktop) go off.

Then I put the N900 in the Qi charging station and its supposed to start charging. There is not sign showing that it's doing so, since the battery indicator doesn't monitor the process any more. Neither the usual yellow bar signal indicating that the process has started (or ended) shows in the screen. The N900's notification LED lights up in orange colour, but does not blink as expected, it just keeps steady on. This the only sign that indicates that 'something' is happening.

The phone looks really neat because the Qi coil charger stays behind the original n900 cover stuck to the Nokia battery. Only a small part (7mm or so) of the ribbon is visible as it reaches the black and very flat micro USB conector, so this mod is barely noticeable. Since the Qi receiver (I've got the X02 variety) has the ribbon protruding from the side of the coil pad, it easily clears the camera area as it reachs the MicroUSB plug. No folding of the ribbon was necessary, only a small cut was made in the plastic protector sheet in order to not been shown through the camera opening hatch, but this was made purely in aesthetics.

Definitively, it charges wirelessly. I've checked twice... and it seems that it does at a good speed. The trade off is I can't tell the actual level of charging due to batt monitors not working unless I reboot the phone. So rebooting is the only way I have figured out to check the level of charge achieved. Annoyingly, It will require to run that script again prior to another wireless charging process. Also, since I didn´t dare to leave the N900 charging wiressly for more than hour, I don´t know if the N900 does stop charging when it gets at the proper level or if it keeps overcharging and eventually damaging the battery or even worse the device itself. Thats a possibility because nothing seems to me to be controlling the charging process. I want to point out than when charging, the N900 gets quite warm, but this is expected since my LG Pad 8.3 tablet behaves in the same way when charging with the same charging solution, and I've been using this method for months with no problems at all. On the other hand, my Galaxy Note 2 does not get so warm when being in the same station. But Note 2 was designed with Qi wireless charge in mind with proper Qi accessories. Note 2 software even detects wireless charging and prompts a message on the screen indicating if the alignment with the wireless charger is correct.

So my questions are: if I follow your method of shortening somehow the data (+/-) pins in a modded microUSB connector, will I be able to monitor the charging process (yellow bar, standard battery monitors and widgets) as if it was charged with the standard way?
Will it stop charging when reached the required level?
Will the notification LED work as usual (blinking orange colour while charging that turns into steady green when the process has ended)?

Although I know the is still room for improvement, I really like the idea of Qi Wireless Charging. My desk is now much more tiddy than the usual mess of chargers and cables it used to be.