As far as who has control of the TV, with my setup I go straight from the cable into the Slingbox by passing my cable box.
This way the wife can be watching the cable box and I can watch something different on the Slingbox. You can only use one Slingplayer at a time though. So if someone is watching Slingplayer on the laptop, you cannot watch it on the wired PC or cellphone.
Overall this is one of the greatest inventions for watching TV. If you want more information here is the link:
http://us.slingmedia.com/page/home
I have been using this since last year to watch all the Kings games when the wife drags me out of the house. If you have any questions feel free to ask.
Mo