Yes, you should definitely stick to one pair because it allows you to focus your concentration. I recommend starting with the USD/JPY. It's one of the most liquid pair and also one of with the tightest spread (not that it matters since you are DEMO trading right?).
I'd recommend EUR/USD as well but the Euro-zone consists of multiple countries so trying to learning fundamentals can get a bit tough. With USD/JPY, you can follow just two countries: US and Japan, and that's tough enough.
First off, piplicious is anything but that... more like pipbusted...
As for the question, I agree, the EUR/USD is good to start off with. I also like trading the cable because itís a little more volatile than the EUR/USD. Be careful though, the spread is slightly bigger.
Another benefit on sticking to one pair is that it allows you to become a specialist. Each pair has its own personality and you can really learn its movement if you stick to one pair. Youíll understand its rhythm and youíll start to get a feel for how it moves at certain times.
Sticking to one pair is favoured, especially you are starting your job in FX.
EURUSD is much easier, but a good point noted above , you got to study more fundamentals. USDJPY is one, couldn't agree more!
Another view could be that if you only want to trade using technicals and not fundamentals than you can look at many pairs assuming you check to make sure there are no major news announements coming out. I personally love the way all our experts here at babypips trade by mixing the fundamental analasys with technicals.