1) you need DVD software to watch DVDs
2) Copying DVDs from the internet is currently illegal UNLESS you download it from the Maker/distributer, and none of them do that - YET.
3) You need a TV card to watch TV through your PC. Hauppage(spelling?) make one, so do other companies.
4) You can't Watch Sky at the moment. Only Freeview through an ariel - You need a dish for Sky and a decoder box.
5) You still need a TV license to watch TV through a PC
6) Copying anything at all for any reason apart from personal use is technically illegal.