Yes, LEDs will still light with very little current.
That gets connected to the negative of your fan. This is probably the black wire in your molex connector.
You can get the code here.
It was written in PicBasic Pro
Everything that is available is shown on the project page. There is no kit for this project.
Yes, the code on the site if the basic one. Please email me for the one you would like.
Please use the 2.56A version of PICBasic Pro.
You can start here.