1) Yes, you could copy material onto your PC via DVD Decrypter, Gordian Knot and then edit out adverts and the like with VDub. The advantage to this is that you could then burn copies onto cheapo DVD-Rs or even store the programmes ready to be put back onto DVD-RW.
I personally have a Philips DVD-R70, about £130, and does a damn good job. Sadly, I believe it only takes DVD+R/RW for recording purposes. However, this isn't really a problem for me.
2) It may well be alright. If you're not initially satisfied with it, you could always take it back within 14 days, as per Argos' policy. If it goes wrong, I'm sure it'll have a years warranty, just like any other product - and there are always duff pieces of equipment, even with the best models!