Summer is not the best season to work on my simulator and so I have just a little update...
I worked on the taxi and landing lights problem...they doesn't work on the Learjet 45 in FSX ... just landing lights work as expected...
Reading this useful post on Hangar45.net portal, http://hangar45.net/index.php?option=com_agora&task=topic&id=257&Itemid=77 and this other one http://www.flightportal.it/forum/viewtopic.php?f=290&t=51327 on flightportal, I was able to run the taxi and landing lights.
Here there are 2 screenshots:
In addition, always reading the Hangar45.net post, I was able to light up "passengers' lights":
Here is a little video of a departure from LIRP, Pisa S. Giusto, which demonstrates my lights configuration.