The kid I got it from says that because of the doubler the stock toyota stick stays all the way down (which is the 4LO position) (it will not go to the 2hi positon, he said trying would bend a rod in the doubler)

Something is not set-up right, that stick is for high/low. The 4 wd is controlled by the back stick on the passenger side, back is 4wd, forward is 2wd.

Where should the sticks be for street driving?

All three back.

Kid also says that for 4wd I need to lock the hubs..other wise ill hurt the t case..

I do not really understand this. To have 4wd you have to lock the hubs. You can run in 2wd with the hubs locked and will not hurt anything. Nice thing about twin sticks is you can shift in and out of 4wd/2wd on the fly. I do it all the time when I am on fireroads. I have had a twin stick in my rig for about 10 years and never had a problem doing it.

Stock stick is for high/low stock gears. High back Low forward.

DS stick is high/low 4:1 High back Low forward.

PS stick 2wd/4wd Back 4wd forward 2wd

OOPS I had the twin stick backwards, I have corrected it.