Can class trials kill or be killed in pvp by other players
If you can enter into pvp combat, you can be killed in pvp combat. The Blizzard guide says you cannot enter raids or low level dungeons, it does not say anything about PvP (and you can enter level dungeons). There are multiple videos showing class trial arena games that I found from a simple search. Class trials are limited to three hours of play time then they are locked out.
Thnks- I have a class trial character and I cannot see a friend of mine of the opposite faction in world PVP on the same server
That might be more sharding than class trial. Since zones are balanced based on population, your friend might have been on a different shard than you were. You might be able to see & fight each other in a different zone.
you can queue for BGs as a trial account and you’ll be in the 20-29 bracket, and also activate War Mode
bear in mind outside of being level 20 you’ll be missing out on the 25 talent and usually a lot of big active/passive abilities in that bracket