5. You should download an app from the store for that, but I don't know if that is available everywhere.
7. No, for me, you can not do that. If you install the STB correct you can access functions from it with the Magic Remote but, in my case, it is not as easy as with the remote from the STB. You can do a lot, but not everything.
Most of the time I use the remote of the STB which I could program to work with the LG TV (volume, on/off). Only when I use apps from the LG TV I use the Magic Remote. If I only want to change a channel or the volume I use the remote close to me :-)