Hi,
I just activated the built in Sirius radio in my LR4, but we don't have a problem with traffic here in Nebraska so I can't really tell you if the traffic notifications will work on the LR4.
As far as the suspension goes, you can lock the system in crawl mode which is access height. There are a couple of problems though: one the ride will be horrible and the second is, once you exceed 25mph the system will raise to standard height.
I know the guys on the LR3 forum talk about a "Rod Mod" suspension lift. They replace all 4 of the rods that connect to the height sensors with shorter rods fooling the computer to lift the truck. I would guess that a similar arrangement could be done in reverse with longer rods that would keep the truck lower than normal. I'm not sure I would advise it, but in theory it should work.
Good luck with the 22s and lowering.
Rob