Check
this thread, there's someone there named chainedfate who's offered to lend his/her account.
I don't personally know the person, I just happened to read your post and the post there and thought maybe I'd link you to each other.
iirc, the GW trial key is only 10 hours or 14 days, whichever comes first. So no, you can't play PVE and then go to PVP in that short manner of time. You can rush Factions and be done with the PVE storyline in less than 10 hours.
You can create a max-level PVP character right at the outset though, so you can use that 10-hour trial to see how the PVP scene is. Mind you though, as the account is "new" you won't have full access to the better/more useful skills, as you'll have to unlock them.
But it is worth a shot to try out
