This is a range extender, not a router--you need a router to get online wirelessly. This will only allow you to extend that router's signal to far away areas that cannot get a good signal on their own due to walls, distance, etc. But YOU NEED A ROUTER first.

You can watch anything and everything you can find on the internet using Chrome as your browser. Some things are blocked--like you can't watch movies on youtube, etc. But if you're savvy and take the time to search the web there are several websites out there where you can watch movies--even movies that are still on in the theatres--as well as TV shows--including pay channel and Netflix only TV shows--online and have your chromcast mirror it on your TV. You are only limited by your imagination and your ability to find content to watch. So basically you can watch anything if you work hard enough at it.

It depends. As long as you're using Chrome as your web browser then anything you look at on the internet should cast right on up to your TV with no problem. Lots of other websites are set up to work with Chromcast as well, and those sites don't even require you to use Chrome as your web browser. Not sure about the various programs that you would use. But you can use an MHL cable to do it as well, and that doesn't require things to be compatible. Just plug your computer into the MHL adapter, and plug the adapter into the HDMI port on your TV, and viola--instant big screen for your computer. Keep in mind that most MHL adapters are set up with a male micro-USB plug on one end and a female HMDI port on the other--so you'll definitely need a standard HDMI cable, and probably an female micro-USB to male USB adapter to use it with your computer. May need to go to Radio Shack for that adapter--not sure if BestBuy will have that or not. And MHL doesn't work with Mac either. Hope this helps. Good luck!